Journal articles: 'Steady condition'

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Leahy, Austin L. "Steady improvement – condition stable." Surgeon 9, no. 6 (December 2011): 299. http://dx.doi.org/10.1016/s1479-666x(11)00139-9.

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Nettleton, R. E. "Information theoretic extended entropy for steady heat condition." Journal of Physics A: Mathematical and General 21, no. 20 (October 21, 1988): 3939–49. http://dx.doi.org/10.1088/0305-4470/21/20/013.

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Narain, A., J. H. Kurita, M. Kivisalu, A. Siemionko, S. Kulkarni, T. W. Ng, N. Kim, and L. Phan. "Internal Condensing Flows inside a Vertical Pipe: Experimental/Computational Investigations of the Effects of Specified and Unspecified (Free) Conditions at Exit." Journal of Heat Transfer 129, no. 10 (February 10, 2007): 1352–72. http://dx.doi.org/10.1115/1.2755063.

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Reported experimental and computational results confirm that both the flow features and heat-transfer rates inside a condenser depend on the specification of inlet, wall, and exit conditions. The results show that the commonly occurring condensing flows’ special sensitivity to changes in exit conditions (i.e., changes in exit pressure) arises from the ease with which these changes alter the vapor flow field in the interior. When, at a fixed steady mass flow rate, the exit pressure is changed from one steady value to another, the changes required of the interior vapor flow toward achieving a new steady duct flow are such that they do not demand a removal of the new exit pressure imposition back to the original steady value—as is the case for incompressible single phase duct flows with an original and “required” exit pressure. Instead, new steady flows may be achieved through appropriate changes in the vapor/liquid interfacial configurations and associated changes in interfacial mass, heat-transfer rates (both local and overall), and other flow variables. This special feature of these flows has been investigated here for the commonly occurring large heat sink situations, for which the condensing surface temperature (not heat flux) remains approximately the same for any given set of inlet conditions while the exit-condition changes. In this paper’s context of flows of a pure vapor that experience film condensation on the inside walls of a vertical tube, the reported results provide an important quantitative and qualitative understanding and support an exit-condition-based categorization of the flows. Experimental results and selected relevant computational results that are presented here reinforce the fact that there exist multiple steady solutions (with different heat-transfer rates) for multiple steady prescriptions of the exit condition—even though the other boundary conditions do not change. However, for some situations that do not fix any specific value for the exit condition (say, exit pressure) but allow the flow the freedom to choose any exit pressure value within a certain range, experiments confirm the computational results that, given enough time, there typically exists, under normal gravity conditions, a self-selected “natural” steady flow with a natural exit condition. This happens if the vapor flow is seeking (or is attracted to) a specific exit condition and the conditions downstream of the condenser allow the vapor flow a range of exit conditions that includes the specific natural exit condition of choice. However, for some unspecified exit-condition cases involving partial condensation, even if computations predict that a natural exit-condition choice exists, the experimental arrangement employed here does not allow the flow to approach its steady natural exit-condition value. Instead, it only allows oscillatory exit conditions leading to an oscillatory flow. For the reported experiments, these oscillatory pressures are induced and imposed by the instabilities in the system components downstream of the condenser.

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Rossen, William Richard, and Johannes Bruining. "Foam Displacements with Multiple Steady States." SPE Journal 12, no. 01 (March 1, 2007): 5–18. http://dx.doi.org/10.2118/89397-pa.

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Summary A number of experimental and theoretical studies suggest that the fractional-flow function for foam can be either multivalued in water saturation or else can comprise distinct fractional-flow curves for two or more foam regimes, with jumps between them where each regime reaches its limiting condition. We construct fractional-flow solutions for these cases. When such a foam is employed in a surfactant-alternating-gas (SAG) process, the usual "tangency" condition is modified and the foam can be considerably weaker than the foam formed at what appears to be the point of tangency of the multivalued fractional-flow function. If the capillary-pressure function Pc (Sw) differs between foam regimes, that difference can substantially change the nature of the displacement. This alters the effective fractional-flow function and hence the global solution of the equations. It is therefore important to determine how capillary pressure varies in foam displacements, by direct measurement in situ if possible. Special care is needed in numerical simulation of processes using fixed grids if capillary pressure depends directly on foam regime. Using gridblocks that are too large can weaken the effect of capillary pressure that would enforce the correct shock on the small scale. Using an upscaled fractional-flow function appears to eliminate this problem, however. Introduction Foams are injected into geological formations for gas diversion in improved oil recovery (IOR) (Schramm 1994; Rossen 1996), acid diversion in matrix acid well stimulation (Gdanski 1993), and environmental remediation (Hirasaki et al. 2000). In IOR and environmental remediation, it is often useful to inject gas and surfactant solution in alternating slugs, a process called SAG injection. SAG injection holds several advantages over continuous coinjection of gas and liquid, as described elsewhere (Shi and Rossen 1998; Shan and Rossen 2004). Method of Characteristics and Fractional-Flow Theory. Many problems involving conservation equations can be formulated in the so-called hyperbolic framework. The ensuing equations can then be solved using the method of characteristics (see, for example, Smoller (1980), after page 266). The solution consists of rarefactions or spreading waves, constant states, and shocks. Additional conditions are also required to obtain a unique solution. Numerical solutions of the equations can, in effect, pick out the wrong uniqueness conditions and give inaccurate results. A complete analysis requires the traveling-wave representation of a shock. Bruining and Van Duijn (2000, 2007) present an example in which the conditions on the traveling wave are essential to identifying the correct solution of the macroscopic equations. Bruining et al. (2002, 2004) give a regularization procedure for constructing such a traveling wave solution for an application of steam injection. The conditions on the traveling wave must be kept in mind when using a graphical procedure for finding the solution with the method of characteristics, a technique introduced by Buckley and Leverett (1941). It is widely used for petroleum engineering applications [see also Pope (1980), who generalized fractional-flow theory to deal with more complex problems]. In this formulation, the uniqueness condition is called the Welge tangent condition (1952).

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Zhao, Fu Zhou, Rong Liang, and Xiao Ping Chen. "Study on Steady Condition Control of Hybrid Turbocharging System." Advanced Materials Research 139-141 (October 2010): 1941–44. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.1941.

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This paper analyzes the principle of hybrid turbocharging system in a vehicle diesel engine, and proposes motor control model about hybrid turbocharging system in steady engine operation condition according to energy imbalance of the exhaust gas. The high-speed motor can work as a motor or a generator in this control model of different engine condition. Then mapping algorithms about n-dimensional linear interpolation and BP neural network are presented to solve steady condition control problem of the hybrid turbocharging system. Each algorithm is applied to map same sample data, the simulation results reveal that BP neural network mapping algorithm is more suitable for the mapping control of hybrid turbocharging system because BP neural network has better generalization ability and faster processing speed.

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Mao, X., H. M. Blackburn, and S. J. Sherwin. "Optimal inflow boundary condition perturbations in steady stenotic flow." Journal of Fluid Mechanics 705 (March 1, 2012): 306–21. http://dx.doi.org/10.1017/jfm.2012.58.

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AbstractWe determine optimal inflow boundary perturbations to steady flow through a straight inflexible tube with a smooth axisymmetric stenosis at a bulk-flow Reynolds number $\mathit{Re}= 400$, for which the flow is asymptotically stable. The perturbations computed produce an optimal gain, i.e. kinetic energy in the domain at a given time horizon normalized by a measure of time-integrated energy on the inflow boundary segment. We demonstrate that similarly to the optimal initial condition problem, the gain can be interpreted as the leading singular value of the forward linearized operator that evolves the boundary conditions to the final state at a fixed time. In this investigation we restrict our attention to problems where the temporal profile of the perturbations examined is a product of a Gaussian bell and a sinusoid, whose frequency is selected to excite axial wavelengths similar to those of the optimal initial perturbations in the same geometry. Comparison of the final state induced by the optimal boundary perturbation with that induced by the optimal initial condition demonstrates a close agreement for the selected problem. Previous works dealing with optimal boundary perturbation considered a prescribed spatial structure and computed an optimal temporal variation of a wall-normal velocity component, whereas in this paper we consider the problem of a prescribed temporal structure and compute the optimal spatial variation of velocity boundary conditions over a one-dimensional inflow boundary segment. The methodology is capable of optimizing boundary perturbations in general non-parallel two- and three-dimensional flows.

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Li, Z. W., and X. L. Yang. "Stability of 3D slope under steady unsaturated flow condition." Engineering Geology 242 (August 2018): 150–59. http://dx.doi.org/10.1016/j.enggeo.2018.06.004.

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BARENBLATT, G. I., M. BERTSCH, and L. GIACOMELLI. "Steady and quasi-steady thin viscous flows near the edge of a solid surface." European Journal of Applied Mathematics 21, no. 3 (May 7, 2010): 253–70. http://dx.doi.org/10.1017/s0956792510000124.

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A new approach is proposed for the description of thin viscous flows near the edges of a solid surface. For a steady flow, the lubrication approximation and the no-slip condition are assumed to be valid on most of the surface, except for relatively small neighbourhoods of the edges, where a universality principle is postulated: the behaviour of the liquid in these regions is universally determined by flux, external conditions and material properties. The resulting mathematical model is formulated as an ordinary differential equation involving the height of the liquid film and the flux as unknowns, and analytical results are outlined. The form of the universal functions which describe the behaviour in the edge regions is also discussed, obtaining conditions of compatibility with lubrication theory for small fluxes. Finally, an ordinary differential equation is introduced for the description of intermediate asymptotic profiles of a liquid film which flows off a bounded solid surface.

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Lauermann, Stephan, Georg Nöldeke, and Thomas Tröger. "The Balance Condition in Search‐and‐Matching Models." Econometrica 88, no. 2 (2020): 595–618. http://dx.doi.org/10.3982/ecta8356.

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Most of the literature that studies frictional search‐and‐matching models with heterogeneous agents and random search investigates steady state equilibria. Steady state equilibrium requires, in particular, that the flows of agents into and out of the population of unmatched agents balance. We investigate the structure of this balance condition, taking agents' matching behavior as given. Building on the “fundamental matching lemma” for quadratic search technologies in Shimer and Smith (2000), we establish existence, uniqueness, and comparative statics properties of the solution to the balance condition for any search technology satisfying minimal regularity conditions. Implications for the existence and structure of steady state equilibria in the Shimer–Smith model and extensions thereof are noted. These reinforce the point that much of the structure of search‐and‐matching models with quadratic search technologies carries over to more general search technologies.

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Tesfa, B., R. Mishra, Feng Shou Gu, and Andrew Ball. "Condition Monitoring of CI Engine Running on Biodiesel Using Transient Process." Key Engineering Materials 413-414 (June 2009): 495–503. http://dx.doi.org/10.4028/www.scientific.net/kem.413-414.495.

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Various research groups across the globe have developed models for engine condition monitoring and fault diagnosis based on the data from steady state performance measurements over the last two decade. However, these performance data are not amenable for easy collection in some situations and some of the data may show little performance deviation at the steady state conditions of operation. The aim of this study is to identify engine operating conditions and parameters that can be used to develop a diagnostic tool for internal combustion (CI) engine running on biodiesel blends fuel. Ricardo Wave Software was used to stimulate healthy and degraded engine. The degraded condition of operation was created by forcing one injector to work with 90%, 80% and 70% of the normal fuel flow efficiency. The measurable performance parameters such as brake power, brake torque and exhaust temperature and CO emission have been used to compare the deviations during steady and transient condition. From the comparison of the data obtained from transient and steady state simulation of the engine with and without injector fault, it can be concluded that the transient parameters show higher deviations and hence are better suited for condition monitoring and diagnostic modelling in engine working speed.

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PAGE, M. A., and E. R. JOHNSON. "Steady nonlinear diffusion-driven flow." Journal of Fluid Mechanics 629 (June 15, 2009): 299–309. http://dx.doi.org/10.1017/s002211200900679x.

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An imposed normal temperature gradient on a sloping surface in a viscous stratified fluid can generate a slow steady flow along a thin ‘buoyancy layer’ against that surface, and in a contained fluid the associated mass flux leads to a broader-scale ‘outer flow’. Previous analysis for small values of the Wunsch–Phillips parameter R is extended to the nonlinear case in a contained fluid, when the imposed temperature gradient is comparable with the background temperature gradient. As for the linear case, a compatibility condition relates the buoyancy-layer mass flux along each sloping boundary to the outer-flow temperature gradient. This condition allows the leading-order flow to be determined throughout the container for a variety of configurations.

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LE ROUX, C. "STEADY STOKES FLOWS WITH THRESHOLD SLIP BOUNDARY CONDITIONS." Mathematical Models and Methods in Applied Sciences 15, no. 08 (August 2005): 1141–68. http://dx.doi.org/10.1142/s0218202505000686.

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We prove the existence, uniqueness and continuous dependence on the data of weak solutions to boundary-value problems that model steady flows of incompressible Newtonian fluids with wall slip in bounded domains. The flows satisfy the Stokes equations and a nonlinear slip boundary condition: for slip to occur, the magnitude of the tangential traction must exceed a prescribed threshold, which is independent of the normal stress, and where slip occurs the tangential traction is equal to a prescribed, possibly nonlinear, function of the slip velocity. In addition, a Dirichlet condition is imposed on a component of the boundary if the domain is rotationally symmetric. The method of proof is based on a variational inequality formulation of the problem and fixed point arguments which utilize wellposedness results for the Stokes problem with a slip condition of the "friction type".

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Chao, An-Chong, Hsing-Ya Li, Guo-Syong Chuang, and Pang-Yen Ho. "A Positive Real Eigenvalue Condition for the Determination of Unstable Steady States in Chemical Reaction Networks." Zeitschrift für Naturforschung A 63, no. 12 (December 1, 2008): 778–90. http://dx.doi.org/10.1515/zna-2008-1205.

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The interesting dynamical behaviours exhibiting in chemical reaction systems, such as multiple steady states and undamped oscillations, often result from unstable steady states. A positive real eigenvalue condition is proposed which gives a necessary and sufficient condition for the determination of an unstable steady state having a positive real eigenvalue in general isothermal reaction networks. Formulas are developed to construct an unstable steady state and a set of positive rate constants. The applications are illustrated by three examples. Two give rise to oscillations and one admits multiple steady states.

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Cavalcanti, S., P. Bolelli, and E. Belardinelli. "Pressure Drops Through Arterial Stenosis Models in Steady Flow Condition." Journal of Biomechanical Engineering 114, no. 3 (August 1, 1992): 416–18. http://dx.doi.org/10.1115/1.2891404.

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Measures of pressure drops were made in two different plexiglass models of axial-symmetric arterial stenoses. The stenosis models had the same are reduction (86 percent) but were of different length so as to have a different tapering degree. Pressures were measured in steady flow condition at three equidistant points of the stenosis: upstream, in the middle, and downstream. Results indicate that: the upstream-middle pressure drop is independent of tapering degree but is highly influenced by area reduction; moreover it is much greater than the middle-downstream drop. The upstream-middle pressure drop can be accurately predicted by means of a relationship deduced by the momentum equation.

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Guo, Lianggang, and He Yang. "Towards a steady forming condition for radial–axial ring rolling." International Journal of Mechanical Sciences 53, no. 4 (April 2011): 286–99. http://dx.doi.org/10.1016/j.ijmecsci.2011.01.010.

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Takeda, Akihide, and Nobuaki Ikuta. "Spatially Resolved Electron Swarm Behavior in Steady State Townsend Condition." Journal of the Physical Society of Japan 70, no. 3 (March 15, 2001): 678–88. http://dx.doi.org/10.1143/jpsj.70.678.

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Castiglioni, Paolo, and Marco Di Rienzo. "How to check steady-state condition from cardiovascular time series." Physiological Measurement 25, no. 4 (July 23, 2004): 985–96. http://dx.doi.org/10.1088/0967-3334/25/4/016.

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Zhang, Xiaoqian, Zheng Yan, and Qi Guo. "Study on Microscopic Mechanism of Electrokinetic Coupling under Steady Condition." IOP Conference Series: Materials Science and Engineering 677 (December 10, 2019): 052046. http://dx.doi.org/10.1088/1757-899x/677/5/052046.

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Madžar, Dominik, Christian Maihöfner, Rüdiger Zimmermann, Stefan Schwab, Johannes Kornhuber, and Piotr Lewczuk. "Cerebrospinal fluid under non-steady state condition caused by plasmapheresis." Journal of Neural Transmission 118, no. 2 (November 16, 2010): 219–22. http://dx.doi.org/10.1007/s00702-010-0519-z.

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Igari, Toshihide, Katsuya Setoguchi, and Shinichi Nomura. "Simplified creep analysis of perforated plates under steady creep condition." Nuclear Engineering and Design 97, no. 2 (November 1986): 161–66. http://dx.doi.org/10.1016/0029-5493(86)90105-6.

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Hu, Qin, Gaohui He, Lichun Shu, Xingliang Jiang, Yanqing Liu, Yongfu Li, Huadong Peng, and Weiwei Wu. "Minimum steady corona inception voltage calculation method under rain condition." IET Generation, Transmission & Distribution 12, no. 8 (April 30, 2018): 1783–89. http://dx.doi.org/10.1049/iet-gtd.2017.0590.

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Sarswat, Meenakshi, and Lokesh Varshney. "An Identification of Magnetizing Current Phenomenon in Steady State Condition." International Journal of Engineering and Advanced Technology 10, no. 5 (June 30, 2021): 151–53. http://dx.doi.org/10.35940/ijeat.e2604.0610521.

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This document is basically based on the magnetizing current phenomenon of transformer. In this paper we will see how the magnetizing current behave when the core material has linear and non-linear characteristics.

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Schuster, Stefan, and Ronny Schuster. "A generalization of Wegscheider's condition. Implications for properties of steady states and for quasi-steady-state approximation." Journal of Mathematical Chemistry 3, no. 1 (January 1989): 25–42. http://dx.doi.org/10.1007/bf01171883.

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PAGE, M. A., and E. R. JOHNSON. "On steady linear diffusion-driven flow." Journal of Fluid Mechanics 606 (July 10, 2008): 433–43. http://dx.doi.org/10.1017/s002211200800178x.

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Wunsch (1970) and Phillips (1970) (Deep-Sea Res. vol. 17, pp. 293, 435) showed that a temperature flux condition on a sloping non-slip surface in a stratified fluid can generate a slow steady upward flow along a thin ‘buoyancy layer’. Their analysis is extended here to the more-general case of steady flow in a contained fluid where buoyancy layers may expel or entrain fluid from their outer edge. A compatibility condition that relates the mass flux and temperature gradient along that edge is derived, and this allows the fluid recirculation and temperature perturbation to be determined in the broader-scale ‘outer flow’ region. The analysis applies when the Wunsch–Phillips parameter R is small, in the linear case for which the density variations are dominated by a constant vertical gradient.

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Aw Lin, Chou, Fatimah Al-Zahrah Mohd Sa’at, Fadhilah Shikh Anuar, Mohamad Firdaus Sukri, Mohd Zaid Akop, and Zainuddin Abdul Manan. "Heat Transfer Across Tube Banks With a Passive Control Vortex Generator in Steady One-Directional and Oscillatory Flows." CFD Letters 13, no. 1 (January 31, 2021): 1–18. http://dx.doi.org/10.37934/cfdl.13.1.118.

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Fluid can flow in one-directional (normal flow) or oscillatory conditions. Fluid flow in some energy system involved oscillatory flow condition. The use of vortex generator has been proven to improve heat transfer in the case of one-directional flow but the impact of vortex generator in oscillatory flow condition is yet unknown. This study focusses on the heat transfer performance across a heated tube banks using a Computational Fluid Dynamics (CFD) model. Two flow conditions were modelled: steady one-directional and oscillatory flow conditions. Two-dimensional CFD models of steady flow and oscillatory flow were solved using the SST k-? turbulence model for two different cases of heated tube banks with and without the vortex generators. The heat transfer performance for both flow conditions were analysed by considering a heat transfer parameter known as Colburn-j factor. Results showed that the use of a vortex generator increased the heat transfer enhancement, regardless of the flow conditions. However, it is also noted that the heat transfer behaviour in a steady flow and an oscillatory flow is not the same, especially with the appearance of secondary flows in the system. The difference is discussed with respect to dimensionless quantity of Colburn j-factor, the non-dimensionless quantity, and the amplitude of temperature field. The result indicates that the heat equation in the steady flow condition is not very suitable to be directly used in oscillatory flow conditions. Appropriate heat equation needs to be properly addressed for situations that involve oscillatory flow motion.

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Sudi Mungkasi. "Modelling And Simulation of Topical Drug Diffusion in The Dermal Layer of Human Body." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 86, no. 2 (August 24, 2021): 39–49. http://dx.doi.org/10.37934/arfmts.86.2.3949.

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We consider the problem of drug diffusion in the dermal layer of human body. Two existing mathematical models of the drug diffusion problem are recalled. We obtain that the existing models lead to inconsistent equations for the steady state condition. We also obtain that solutions to the existing models are unrealistic for some cases of the unsteady state condition, because negative drug concentrations occur due to the inappropriate assumption of the model. Therefore, in this paper, we propose a modified mathematical model, so that the model is consistent, and the solution is nonnegative for both steady and unsteady state conditions of the drug diffusion problem in the dermal layer of human body. For the steady state condition, the exact solution to the proposed model is given. For unsteady state condition, we use a finite difference method for solving the models numerically, where the discretisation is centred in space and forward in time. Simulation results confirm that our proposed model and method preserve the non-negativity of the solution to the problem, so the solution is more realistic than that of the old model.

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Benhabib, Jess, and Bálint Szoőke. "Optimal Positive Capital Taxes at Interior Steady States." American Economic Journal: Macroeconomics 13, no. 1 (January 1, 2021): 114–50. http://dx.doi.org/10.1257/mac.20180191.

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We generalize recent results of Bassetto and Benhabib (2006) and Straub and Werning (2019) in a neoclassical model with endogenous labor-leisure choice where all agents are allowed to save and accumulate capital. We provide a sufficient condition under which optimal redistributive capital taxes remain at their allowed upper bound forever, even if the resulting equilibrium trajectory converges to a unique steady state with positive and finite consumption, capital, and labor. We then provide an interpretation of our sufficient condition. Using recent evidence on wealth distribution in the United States, we argue that our sufficient condition is empirically plausible. (JEL D31, E21, H21, H23, H25, J22)

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Pumo, D., F. Viola, and L. V. Noto. "Ecohydrology in Mediterranean areas: a numerical model to describe growing seasons out of phase with precipitations." Hydrology and Earth System Sciences 12, no. 1 (February 27, 2008): 303–16. http://dx.doi.org/10.5194/hess-12-303-2008.

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Abstract. The probabilistic description of soil moisture dynamics is a relatively new topic in hydrology. The most common ecohydrological models start from a stochastic differential equation describing the soil water balance, where the unknown quantity, the soil moisture, depends both on spaces and time. Most of the solutions existing in literature are obtained in a probabilistic framework and under steady-state condition; even if this last condition allows the analytical handling of the problem, it has considerably simplified the same problem by subtracting generalities from it. The steady-state hypothesis, appears perfectly applicable in arid and semiarid climatic areas like those of African's or middle American's savannas, but it seems to be no more valid in areas with Mediterranean climate, where, notoriously, the wet season foregoes the growing season, recharging water into the soil. This moisture stored at the beginning of the growing season (known as soil moisture initial condition) has a great importance, especially for deep-rooted vegetation, by enabling survival in absence of rainfalls during the growing season and, however, keeping the water stress low during the first period of the same season. The aim of this paper is to analyze the soil moisture dynamics using a simple non-steady numerical ecohydrological model. The numerical model here proposed is able to reproduce soil moisture probability density function, obtained analytically in previous studies for different climates and soils in steady-state conditions; consequently it can be used to compute both the soil moisture time-profile and the vegetation static water stress time-profile in non-steady conditions. Here the differences between the steady-analytical and the non-steady numerical probability density functions are analyzed, showing how the proposed numerical model is able to capture the effects of winter recharge on the soil moisture. The dynamic water stress is also numerically evaluated, implicitly taking into account the soil moisture condition at the beginning of the growing season. It is also shown the role of different annual climatic parameterizations on the soil moisture probability density function and on the vegetation water stress evaluation. The proposed model is applied to a case study characteristic of Mediterranean climate: the watershed of Eleuterio in Sicily (Italy).

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Sutikno, Sutikno. "STEADY STATE CONDITION PREDICTION OF ECONOMIC GROWTH IN EAST JAVA REGION." Jurnal Ekonomi Pembangunan 17, no. 2 (January 31, 2020): 164. http://dx.doi.org/10.22219/jep.v17i2.11063.

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The quality of development of a country or region is not only seen from the high level of economic growth, but also the higher level of economic growth produced by people in a country or region. One of the economic development debates in East Java in the last few decades is the imbalance of development between regions. This article focuses its analysis on the value of "stable conditions" districts / cities in East Java in reducing income disparity between regions. The analysis in this study is a convergence analysis conducted in East Java Province using a conditional convergence test with observations of all districts and cities in East Java. Variable interest is income per capita. Variable gross fixed investment, net exports, labor force, capital expenditure, human development index. The success variable is the average economic growth in 2010-2018. Whereas the theory underlying all these variables is the Solow-Swan classical economic growth model. The convergence speed results explain the convergence speed in East Java Province by 4.8 percent. Regarding income per capita in developing countries which must grow at least 4.8 percent per year for the Java economy to reach a stable point. The amount of time needed to cover half of the initial period (half-life of convergence) is 6.2 years

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ISLAM, Kh Shafiul, and Teruyuki FUKUHARA. "HEAT AND MASS TRANSFER IN TUBULAR SOLAR STILL UNDER STEADY CONDITION." PROCEEDINGS OF HYDRAULIC ENGINEERING 49 (2005): 727–32. http://dx.doi.org/10.2208/prohe.49.727.

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Singh, Shashi Bhushan, and Asheesh K. Singh. "Steady-state Performance Assessment of Induction Motor under Unbalanced Voltage Condition." Electric Power Components and Systems 41, no. 13 (October 3, 2013): 1248–63. http://dx.doi.org/10.1080/15325008.2013.817492.

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Jain, Arvind. "Injector requirements and radial magnet condition for a steady state MIGMA." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 323, no. 3 (December 1992): 671–76. http://dx.doi.org/10.1016/0168-9002(92)90013-t.

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Calsina, Àngel, and József Z. Farkas. "Steady states in a structured epidemic model with Wentzell boundary condition." Journal of Evolution Equations 12, no. 3 (March 16, 2012): 495–512. http://dx.doi.org/10.1007/s00028-012-0142-6.

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Sedev, R. V., and J. G. Petrov. "The critical condition for transition from steady wetting to film entrainment." Colloids and Surfaces 53, no. 1 (January 1991): 147–56. http://dx.doi.org/10.1016/0166-6622(91)80041-l.

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Krutova, Veronika, and Besarion Meskhi. "VIBRATIONS OF THE CLOSED FRAME STRUCTURES IN A STEADY-STATE CONDITION." Akustika, VOLUME 41 (2021): 4–7. http://dx.doi.org/10.36336/akustika2021414.

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The load-bearing frames of the technological machinery of various functional purposes, such as bridge and gantry cranes, locomotives, motor locomotives, etc., are energetically closed rod systems [1-10].

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Abidat, M., M. Hachemi, M. K. Hamidou, and N. C. Baines. "Prediction of the steady and non-steady flow performance of a highly loaded mixed flow turbine." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 212, no. 3 (May 1, 1998): 173–84. http://dx.doi.org/10.1243/0957650981536844.

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This paper describes a method for predicting the performance under both turbine inlet steady state and non-steady state flow conditions of a mixed flow turbine used for turbocharged internal combustion engines. The mixed flow turbine steady state performances computed with the steady state performance prediction method are in good agreement with the experimental results obtained in the Imperial College turbocompressor cold air test rig. The unsteady state performance is computed using a one-dimensional model based on the solution of the unsteady one-dimensional flow equations. These equations are solved in the volute by a finite difference method using a four-step explicit Runge—Kutta scheme. The instantaneous volute exit condition is provided by the steady state rotor performance prediction model with the assumption of a quasi-steady state flow in the rotor. The computed instantaneous performances are in reasonable agreement with published experimental data for the same mixed flow turbine. The unsteady flow model is also used to study the effects of the frequency and the amplitude of the pulse on the performances of the mixed flow turbine.

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37

Pelesko, J. A. "Nonlinear Stability, Thermoelastic Contact, and the Barber Condition." Journal of Applied Mechanics 68, no. 1 (June 26, 2000): 28–33. http://dx.doi.org/10.1115/1.1345699.

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The behavior of a one-dimensional thermoelastic rod is modeled and analyzed. The rod is held fixed and at constant temperature at one end, while at the other end it is free to separate from or make contact with a rigid wall. At this free end we impose a pressure and gap-dependent thermal boundary condition. This condition, known as the Barber condition, couples the thermal and elastic problems. Such systems have previously been shown to undergo a bifurcation from a unique linearly stable steady-state solution to multiple steady-state solutions with alternating stability. Here, the system is studied using the asymptotic matching techniques of boundary layer theory to derive short-time, long-time, and uniform expansions. In this manner, the analysis is extended into the nonlinear regime and dynamic information about the history dependence and temporal evolution of the solution is obtained.

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Tuck, E. O., and A. Kouzoubov. "A laminar roughness boundary condition." Journal of Fluid Mechanics 300 (October 10, 1995): 59–70. http://dx.doi.org/10.1017/s0022112095003600.

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A modified slip boundary condition is obtained to represent the effects of small roughness-like perturbations to an otherwise-plane fixed wall which is acting as a boundary to steady laminar flow of a viscous fluid. In its simplest form, for low local Reynolds number and small roughness slope, this boundary condition involves a constant apparent backflow at the mean surface or, equivalently, represents a shift of the apparent plane boundary toward the flow domain. Extensions of the theory are also made to include finite local Reynolds number and finite roughness slope.

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Huang, Kai Sheng, Dong Liang Wang, Zhi Hua Lin, and Xiang Rui Zeng. "Engine Torque Estimation Based on BP Neural Network." Advanced Materials Research 403-408 (November 2011): 2848–51. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.2848.

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Engine torque estimation function is the base of engine torque control. This paper establishes the model for engine torque estimation respectively under steady condition and unsteady condition based on BP Neural network, and develops a new engine torque real-time estimation method. The experiment results under steady condition and unsteady condition show that the engine torque estimation model can estimate the engine output torque and the precision is remarkable.

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40

MARRO, J. "STEADY STATES IN NONEQUILIBRIUM LATTICE SYSTEMS." International Journal of Modern Physics C 04, no. 02 (April 1993): 357–64. http://dx.doi.org/10.1142/s0129183193000380.

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Nonequilibrium Ising-like systems may be implemented efficiently in the computer. They may represent some natural situations, and may be relevant towards the development of theory. Three models in which either driving dissipative fields or competing kinetics impede the condition of detailed balance are described, and some related Monte Carlo results are reviewed. The models exhibit rich and interesting novel behavior.

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41

DAVIES, CHRISTOPHER J., DAVID GUBBINS, and PETER K. JIMACK. "Convection in a rapidly rotating spherical shell with an imposed laterally varying thermal boundary condition." Journal of Fluid Mechanics 641 (December 10, 2009): 335–58. http://dx.doi.org/10.1017/s0022112009991583.

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We investigate thermally driven convection in a rotating spherical shell subject to inhomogeneous heating on the outer boundary, extending previous results to more rapid rotation rates and larger amplitudes of the boundary heating. The analysis explores the conditions under which steady flows can be obtained, and the stability of these solutions, for two boundary heating modes: first, when the scale of the boundary heating corresponds to the most unstable mode of the homogeneous problem; second, when the scale is larger. In the former case stable steady solutions exhibit a two-layer flow pattern at moderate rotation rates, but at very rapid rotation rates no steady solutions exist. In the latter case, stable steady solutions are always possible, and unstable solutions show convection rolls that cluster into nests that are out of phase with the boundary anomalies and remain trapped for many thermal diffusion times.

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42

Bovand, Masoud, Saman Rashidi, Masoomeh Dehesht, and Javad Abolfazli Esfahani. "Effect of fluid-porous interface conditions on steady flow around and through a porous circular cylinder." International Journal of Numerical Methods for Heat & Fluid Flow 25, no. 7 (September 7, 2015): 1658–81. http://dx.doi.org/10.1108/hff-10-2014-0295.

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Purpose – The purpose of this paper is to implement the numerical analysis based on finite volume method to compare the effects of stress-jump (SJ) and stress-continuity (SC) conditions on flow structure around and through a porous circular cylinder. Design/methodology/approach – In this study, a steady flow of a viscous, incompressible fluid around and through a porous circular cylinder of diameter “D,” using Darcy-Brinkman-Forchheimer’s equation in the porous region, is discussed. The SJ condition proposed by Ochoa-Tapia and Whitaker is applied at the porous-fluid interface and compared with the traditional interfacial condition based on the SC condition in fluid and porous media. Equations with the relevant boundary conditions are numerically solved using a finite volume approach. In this study, Reynolds and Darcy numbers are varied within the ranges of 1 < Re < 40 and 10-7 < Da < 10-2, respectively, and the porosities are e=0.45, 0.7 and 0.95. Findings – Results show that the SJ condition leads to a much smaller boundary layer within porous medium near the interface as compared to the SC condition. Two interfacial conditions yield similar results with decrease in porosity. Originality/value – There is no published research in the literature about the effects of important parameters, such as Porosity and Darcy numbers on different fluid-porous interface conditions for a porous cylinder and comparison the effects of SJ and SC conditions on flow structure around and through a porous circular cylinder.

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43

Luo, Hong. "Steady State Solution to Atmospheric Circulation Equations with Humidity Effect." Journal of Applied Mathematics 2012 (2012): 1–18. http://dx.doi.org/10.1155/2012/867310.

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The steady state solution to atmospheric circulation equations with humidity effect is studied. A sufficient condition of existence of steady state solution to atmospheric circulation equations is obtained, and regularity of steady state solution is verified.

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44

Li, Hsing-Ya. "Zero Eigenvalue Analysis for the Determination of Multiple Steady States in Reaction Networks." Zeitschrift für Naturforschung A 53, no. 3-4 (April 1, 1998): 171–77. http://dx.doi.org/10.1515/zna-1998-3-411.

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Abstract A chemical reaction network can admit multiple positive steady states if and only if there exists a positive steady state having a zero eigenvalue with its eigenvector in the stoichiometric subspace. A zero eigenvalue analysis is proposed which provides a necessary and sufficient condition to determine the possibility of the existence of such a steady state. The condition forms a system of inequalities and equations. If a set of solutions for the system is found, then the network under study is able to admit multiple positive steady states for some positive rate constants. Otherwise, the network can exhibit at most one steady state, no matter what positive rate constants the system might have. The construction of a zero-eigenvalue positive steady state and a set of positive rate constants is also presented. The analysis is demonstrated by two examples.

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45

Sharma, Deepakkumar M., and Kamal Poddar. "Investigations on Quasi-Steady Characteristics for an Airfoil Oscillating at Low Reduced Frequencies." International Journal of Aerospace Engineering 2010 (2010): 1–11. http://dx.doi.org/10.1155/2010/940528.

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Wind tunnel experiments were conducted on NACA-0015 airfoil model to investigate the effect of the reduced frequency (κ=0.0001to 0.5) and that Reynolds number (Re=0.2E06to 0.7E06) on the aerodynamic characteristics and hysteresis behavior associated with the oscillating motion of the airfoil. Pressure measurements were conducted on the midspan of the airfoil for quantitative results. Although dynamic stall study has been conducted to greater extent of reduced frequencies, for current work, emphasis is made on investigating the low reduced frequency regimes up to which the steady conditions prevail under dynamic mode of operation. In present investigations of oscillating sinusoidalα=10∘+15∘sin(ωt)motion, the airfoil was allowed to execute oscillating motion from static to almost steady (quasi-steady) conditions with the incremental increase in the reduced frequency. The limiting conditions ofκandRefor quasi-steady state are carefully extracted and analyzed. Static and quasi-steady conditions are critically assessed in context of the existence of laminar separation bubble within the optedReregime. The flow separation was found to be trailing edge flow separation with existence of LSB upstream towards the leading edge with no evidence of unsteady flow reversals. Normal force defect and pitch damping factor are estimated for varied range ofReandκwithin the quasi-steady conditions. Re effect is dominant at steady and quasi-steady regimes while the effect of reduced frequency is negligible in this domain. Minor hysteresis effect associated with the stalling and reattachment point is due to existence of weak stall flutter which is further restrained by the oscillatory motion of the airfoil. Laminar separation bubble traced during steady condition is conserved in quasi-steady domain as well.

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Li, Y., S. Zuo, X. Duan, X. Guo, and C. Jiang. "Theory analysis of the steady-state surface temperature on rolling tire." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 226, no. 5 (October 3, 2011): 1278–89. http://dx.doi.org/10.1177/0954406211422000.

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The mechanisms of heat generation and heat dissipation of tire are first discussed, and the heat generation capacity and the heat dissipation capacity per unit time are obtained through the analysis of both tire contact pressure distribution and heat dissipation method. Then,according to heat balance condition of tire, the theory model of the steady-state surface temperature of tire is established based on tire temperature field tests. Finally, the effects of speed, load, and tire pressure on the steady-state surface temperature of tire are analysed. The results show that the established model of the steady-state surface temperature of rolling tire is feasible, and the results can reflect the thermal conditions of tire, and therefore provides a theoretical foundation to predict the steady-state surface temperature for various types of tires under different driving conditions.

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Sweger, P. O., C. L. Anderson, and J. R. Blough. "Measurements of Strain on 310 mm Torque Converter Turbine Blades." International Journal of Rotating Machinery 10, no. 1 (2004): 55–63. http://dx.doi.org/10.1155/s1023621x04000065.

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An automotive torque converter was tested in order to determine the effect of converter operating condition and turbine blade design on turbine blade strain in the region of the inlet core tab restraint. The converter was operated over a wide range of speed ratios (0 to 0.95) at constant input torque and a stall condition for two input torques. Foil-type strain gages in combination with wireless microwave telemetry were used to measure surface strain on the turbine blade. Strain measurements were made on two turbine blade designs.The steady component of strain over the range of speed ratios suggests the effect of both torque loading and centrifugal loading on the turbine blade tip. The unsteady strain was greatest at stall condition and diminished as speed ratio increased. Greater input torque at stall condition resulted in both greater steady strain and greater unsteady strain. The spectral distribution of strain over the range of tested speed ratios displayed an increase in low-frequency broadband fluctuations near stall condition. A blade-periodic event is observed which correlates to the pump-blade passing frequency relative to the turbine rotating frame. Reducing the blade-tip surface area and increasing the inlet-tab root radius reduced the range of steady strain and magnitude of unsteady strain imposed near the inlet core tab restraint over the range of operating conditions.

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48

Rasool, Aazim, Xiangwu Yan, Haaris Rasool, Hongxia Guo, and Mansoor Asif. "VSG Stability and Coordination Enhancement under Emergency Condition." Electronics 7, no. 9 (September 17, 2018): 202. http://dx.doi.org/10.3390/electronics7090202.

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Renewable energy sources are integrated into a grid via inverters. Due to the absence of an inherent droop in an inverter, an artificial droop and inertia control is designed to let the grid-connected inverters mimic the operation of synchronous generators and such inverters are called virtual synchronous generators (VSG). Sudden addition, removal of load or faults in the grid causes power and frequency oscillations in the grid. The steady state droop control of VSG is not effective in dampening such oscillations. Therefore, a new control scheme, namely bouncy control, has been introduced. This control uses a variable emergency gain, to enhance or reduce the power contribution of individual VSGs during a disturbance. The maximum power contribution of an individual VSG is limited by its power rating. It has been observed that this control, successfully minimized the oscillation of electric parameters and the power system approached steady state quickly. Therefore, by implementing bouncy control, VSGs can work in coordination to make the grid more robust. The proposed controller is verified through Lyapunov stability analysis.

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Kou, Guiyue, Xinghu Li, Yan Wang, Mouyou Lin, Chunsen Tan, and Mingfei Mou. "Steady performance and dynamic characteristics of a superellipse groove dry gas seal at a high-speed condition." Industrial Lubrication and Tribology 72, no. 6 (March 14, 2020): 789–96. http://dx.doi.org/10.1108/ilt-05-2019-0171.

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Purpose The purpose of this paper is to enhance film stiffness and control seal leakage of conventional spiral groove dry gas seal (S-DGS) at a high-speed condition by introducing a new type superellipse surface groove. Design/methodology/approach The steady-state performance and dynamic characteristics of superellipse groove dry gas seal and S-DGS are compared numerically at a high-speed condition. The optimized superellipse grooves for maximum steady-state film stiffness and dynamic stiffness coefficient are obtained. Findings Properly designed superellipse groove dry gas seal provides remarkable larger steady-state film stiffness, dynamic stiffness coefficient and lower leakage rate at a high-speed condition compared to a typical S-DGS. The optimal values of first superellipse coefficient for maximum steady and dynamic stiffness are 1.3 and 1.4, whereas the optimal values of second superellipse coefficient for which are 1.4 and 2.0, respectively. Originality/value A new type of molded line, namely, superellipse curve, is proposed to act as the boundary lines of surface groove of dry gas seal, as an alternative of typical logarithm helix. The conclusions provide references for surface groove design with larger stiffness and lower leakage rate at a high-speed condition.

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Lee-Young, J. S., and J. F. A. Sleath. "INITIAL MOTION IN COMBINED WAVE AND CURRENT FLOWS." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 85. http://dx.doi.org/10.9753/icce.v21.85.

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Measurements are presented of the conditions for the initial motion of sediment under combined steady and oscillatory flow. The measurements were made in a steady flow flume with an oscillating tray set into its bed. The direction of oscillation of the tray was at right angles to the axis of the steady flow flume. Four different grades of sand were tested. It is found that the critical condition for the initiation of motion is reasonably represented by a critical value of the vector sum of the component shear stresses assuming no nonlinear interaction between the steady and oscillatory flows. The resultant bed shear stress was also calculated with the aid of several combined wave-current models. The results of these various approaches are compared with Shields curve.

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Journal articles on the topic 'Steady condition'

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