Academic literature on the topic 'Jet transport container'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Jet transport container.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Jet transport container"
1
RAMESH, NIRAJA, SAM W. JOSEPH, LEWIS E. CARR, LARRY W. DOUGLASS, and FREDRICK W. WHEATON. "Serial Disinfection with Heat and Chlorine To Reduce Microorganism Populations on Poultry Transport Containers." Journal of Food Protection 66, no. 5 (May 1, 2003): 793–97. http://dx.doi.org/10.4315/0362-028x-66.5.793.
Full textAbstract:
A prototype system for the cleaning and decontamination of poultry transport containers was previously developed and evaluated as a means of eliminating foodborne pathogens entering poultry processing plants. While decontamination of the containers once with the use of either hot water (up to 70°C) or sodium hypochlorite (up to 1,000 ppm) resulted in significant reductions in the numbers of coliforms and the elimination of small numbers of Salmonella, complete removal of pathogens was not attained. Therefore, the present study was conducted to determine whether repeated decontamination of the same containers could eliminate coliforms and Salmonella consistently. Individual five-tier containers consisting of galvanized steel frames and fiberglass floors were identified (n = 6) and decontaminated once per day for five consecutive days after being used to haul broilers from farms to the processing plant. Two types of containers were tested in this study: one had previously been used for broiler transportation, and the other had new floors. After each transport, the containers were first precleaned with a cleaning agent using a high-pressure jet (6,094 kPa) to remove debris and to loosen biofilms from surfaces. The containers were then immersed in an aqueous solution of 1,000 ppm of sodium hypochlorite at 70°C for 2 min. Samples obtained from the container surfaces before and after each cleaning and decontamination were analyzed to obtain coliform and Salmonella counts. Coliforms were completely eliminated from both types of containers following one decontamination treatment. Because no Salmonella were detected on the containers, the effect of decontamination in the elimination of Salmonella was not determined. Similar treatments on five successive days also resulted in poultry transport containers that were essentially free of Salmonella and coliforms. This decontamination system involving a combination of heat and sodium hypochlorite can be used as a standard method for cleaning poultry transport containers in the poultry industry. It is recommended that such containers be cleaned after each use to avoid the potential risk of a buildup of significantly higher loads of pathogenic microorganisms and their biofilms.
2
Vermeulen, Estee Ann, Björn Backeberg, Juliet Hermes, and Shane Elipot. "Investigating the relationship between volume transport and sea surface height in a numerical ocean model." Ocean Science 15, no. 3 (May 14, 2019): 513–26. http://dx.doi.org/10.5194/os-15-513-2019.
Full textAbstract:
Abstract. The Agulhas Current Time-series Experiment mooring array (ACT) measured transport of the Agulhas Current at 34∘ S for a period of 3 years. Using along-track satellite altimetry data directly above the array, a proxy of Agulhas Current transport was developed based on the relationship between cross-current sea surface height (SSH) gradients and the measured transports. In this study, the robustness of the proxy is tested within a numerical modelling framework using a 34-year-long regional hindcast simulation from the Hybrid Coordinate Ocean Model (HYCOM). The model specifically tested the sensitivity of the transport proxy to (1) changes in the vertical structure of the current and to (2) different sampling periods used to calculate the proxy. Two reference proxies were created using HYCOM data from 2010 to 2013 by extracting model data at the mooring positions and along the satellite altimeter track for the box (net) transport and the jet (southwestward) transport. Sensitivity tests were performed where the proxy was recalculated from HYCOM for (1) a period where the modelled vertical stratification was different compared to the reference proxy and (2) different lengths of time periods: 1, 3, 6, 12, 18, and 34 years. Compared to the simulated (native) transports, it was found that the HYCOM proxy was more capable of estimating the box transport of the Agulhas Current compared to the jet transport. This was because the model is unable to resolve the dynamics associated with meander events, for which the jet transport algorithm was developed. The HYCOM configuration in this study contained exaggerated levels of offshore variability in the form of frequently impinging baroclinic anticyclonic eddies. These eddies consequently broke down the linear relationship between SSH slope and vertically integrated transport. Lastly, results showed that calculating the proxy over shorter or longer time periods in the model did not significantly impact the skill of the Agulhas transport proxy. Modelling studies of this kind provide useful information towards advancing our understanding of the sensitivities and limitations of transport proxies that are needed to improve long-term ocean monitoring approaches.
3
Ilisca, Ernest. "Hydrogen Storage in Cryogenic, Cybernetic, and Catalytic Vessels for Transport Vehicles." Journal of Energy and Power Technology 03, no. 04 (June 18, 2021): 1. http://dx.doi.org/10.21926/jept.2104045.
Full textAbstract:
Most of the hydrogen storage vessels meant for vehicles to run the electric motor via a fuel cell during transport are designed for drives of only a few tenths of kilometers per day. The present report, however, describes a vessel model that is conceived to hold the hydrogen energy only for short periods during transport, such as a few hours. This would include transport via a light-duty vehicle, a taxi, or a bus, which would load liquid hydrogen at a station every morning for the day. This is a simple model based on the novel concept of Double Open Vessel (DOV), in which the liquid H2 is loaded inside an open container inserted inside another open container. The walls of this DOV are constituted of simplified linings that allow the entry of thermal heat nearly a hundred times greater than that allowed by the cryo-compressed vessels with higher insulation. After loading, the liquid evaporates, while the gas flows around its initial container into which it was loaded, passes through a few porous plugs, and is gradually released towards the Fuel Cell (or toward an ignition motor). Such a counter-flow of the gas creates a retroaction effect that insulates the inner container, thereby delaying the increases in temperature and pressure. The successive porous plugs installed in the space between the two containers form a system of barrages that regulate the gas flow through successive expansions of decreasing pressures. In addition, these catalytic plugs convert a portion of the loaded hydrogen into its ortho variety, acting as a heat pump, while temporarily storing the other portion. Collectively, these effects maintain the internal pressures below 150 bar. The proposed design for the DOV models is convenient to manufacture and has a lighter weight, and consequently, a low cost.
4
Phuoc, Tran X., and Mehrdad Massoudi. "Harvesting the Potential of CO2 before it is Injected into Geological Reservoirs." Journal of Energy and Power Technology 3, no. 4 (October 28, 2021): 1. http://dx.doi.org/10.21926/jept.2104050.
Full textAbstract:
To store CO2 in geological reservoirs, expansion valves have been used to intentionally release supercritical CO2 from high-pressure containers at a source point to lower-pressure pipelines and transport to a selected injection site. Using expansion valves, however, has some shortcomings: (i) the fluid potential, in the form of kinetic energy and pressure which can produce mechanical work or electricity, is wasted, and (ii) due to the Joule-Thomson cooling effect, the reduction in the temperature of the released CO2 stream might be so dramatic that it can induce thermal contraction of the injection well causing fracture instability in the storage formation. To avoid these problems, it has been suggested that before injection, CO2, should be heated to a temperature slightly higher than that of the reservoir. However, heating could increase the cost of CO2 injection. This work explores the use of a Tesla Turbine, instead of an expansion valve, to harvest the potential of CO2, in the form of its pressure and kinetics, to generate mechanical work when it is released from a high-pressure container to a lower-pressure transport pipeline. The goal is to avoid throttling losses and to produce useful power because of the expansion process. In addition, due to the friction between the gas and the turbine disks, the expanded gas temperature reduction is not as dramatic as in the case when an expansion valve is used. Thus, as far as CO2 injection is concerned, the need for preheating can be minimized.
5
Bijvelds, M., Z. Kolar, S. Bonga, and G. Flik. "Mg2+ transport in plasma membrane vesicles of renal epithelium of the Mozambique tilapia (Oreochromis mossambicus)." Journal of Experimental Biology 200, no. 13 (July 1, 1997): 1931–39. http://dx.doi.org/10.1242/jeb.200.13.1931.
Full textAbstract:
To elucidate the mechanisms involved in Mg2+ transport at the apical and basolateral poles of the renal tubular epithelium, apical and basolateral plasma membrane vesicle preparations were derived from kidney tissue of freshwater- and seawater-adapted Mozambique tilapia Oreochromis mossambicus. Brush-border preparations were enriched 15.8-fold in alkaline phosphatase activity and consisted almost exclusively of right-side-out membrane vesicles. Basolateral membrane preparations were enriched 7.5-fold in Na+/K+-ATPase activity and contained resealed vesicles and leaky membrane fragments. Mg2+ association with brush-border and basolateral plasma membranes, traced using radioactive 27Mg, occurred in an osmotically active space. In all instances, Mg2+ binding to the vesicular membrane was low compared with the vesicular uptake. Mg2+ equilibration across the vesicular membrane of brush-border preparations was rapid and sensitive to the presence of extravesicular Ca2+, suggesting that the apical membrane of the renal epithelium contains a transport pathway for divalent cations. Application of various ionic gradients did not affect vesicular Mg2+ transport in apical and basolateral membrane preparations, suggesting the presence of an ion-coupled transport mechanism. ATP or ATP--S did not stimulate Mg2+ fluxes, indicating that Mg2+ transport does not proceed via an ATP-driven or activated transporter. In these aspects, vesicular Mg2+ transport was similar in seawater and freshwater preparations. These results suggest that the apical membrane of renal epithelial cells lacks an active secretory Mg2+ transport mechanism. We propose that the Mg2+ conductivity of the apical membrane reflects a route for downhill Mg2+ entry and is involved in renal Mg2+ reabsorption.
6
CHAMBERLIN, M. E. "Ion Transport Across the Midgut of the Tobacco Hornworm (Manduca Sexta)." Journal of Experimental Biology 150, no. 1 (May 1, 1990): 425–42. http://dx.doi.org/10.1242/jeb.150.1.425.
Full textAbstract:
1. The transport of K+, Na+ and Cl− across the three morphologically distinct regions of the tobacco hornworm midgut was measured under open-circuit and short-circuit conditions. Using a saline which contained physiological levels of haemolymph ions, amino acids and sugars, it was shown that all three sections actively secrete K+ and Cl− and absorb Na+. 2. The anterior section maintained the highest short-circuit current (Isc), transepithelial potential difference (PD) and net K+ secretion. The middle section had the lowest Isc, PD and K+ secretion, but absorbed Na+ at the greatest rate. The posterior section had the greatest rate of Cl− secretion. 3. Omission of K+ depressed the Isc. Subsequent addition of K+ stimulated the Isc to control levels in the middle and posterior sections, but not in the anterior section. Omission of Cl− or Na+ also inhibited the Isc. Reintroduction of Cl− had no stimulatory effect and, although reintroduction of Na+ stimulated the Isc, control levels were not attained. 4. Unlike the results reported in previous studies, the net K+ transport exceeded the Isc in all three midgut sections. The deficit in Isc was not made up by the transport of Na+ and Cl−. The results are discussed with respect to proposed models of ion transport across this epithelium.
7
Griffith, I. J., N. Nabavi, Z. Ghogawala, C. G. Chase, M. Rodriguez, D. J. McKean, and L. H. Glimcher. "Structural mutation affecting intracellular transport and cell surface expression of murine class II molecules." Journal of Experimental Medicine 167, no. 2 (February 1, 1988): 541–55. http://dx.doi.org/10.1084/jem.167.2.541.
Full textAbstract:
We have selected Ia variants from the Ia+ (H-2d) M12.4.1 B cell lymphoma that are negative on the cell surface for one or both Ia isotypes. The molecular analysis of two such independently selected cell lines, M12.A2 and M12.C3, is reported here. This analysis revealed that the genes encoding Ad beta (M12.A2) and Ed beta (M12.C3) contained identical single-nucleotide transitions that resulted in the substitution of Ser (mutant) for Asn (wild-type) at residue 82/83 of the extracellular NH2-terminal (membrane distal) beta 1 domain. This conservative substitution caused a cytoplasmic accumulation of I-A or I-E molecules in the respective cell line although predicted secondary-structure analysis suggests a minimal effect on protein conformation. Thus, the mutation appears to have either created a negative signal that stops transport or eliminated a positive signal that is required for transport and targeting to the cell surface.
8
Fratini, Danicla. "Modelli di gestione a confronto per le infrastrutture di trasporto di gas naturale." ECONOMIA PUBBLICA, no. 3 (May 2009): 53–87. http://dx.doi.org/10.3280/ep2008-003003.
Full textAbstract:
- In the perspective of the draft proposals of the European Commission contained in the so called Third Energy Package, an assessment of the natural gas transport network organizational models is needed. Particular attention is devoted to the forms of separation between the network manager and the service provider, the relationship between property and management of the network and the ownership regime of such infrastructures. For every profile, different organization models are discussed through a cost and benefit comparison. The objective of the paper is to provide some lessons about the best solutions to assure transparency of the capacity use, security of the system, quality of the service and adequacy of the investment decisions in the natural gas transport infrastructure. JEL L33, L38, L52, L95
9
KULCZYCKI, Andrzej, Wojciech DZIĘGIELEWSKI, and Dariusz OZIMINA. "THE INFLUENCE OF THE CHEMICAL STRUCTURE OF SYNTHETIC HYDROCARBONS AND ALCOHOLS ON THE LUBRICITY OF CI ENGINE FUELS AND AVIATION FUELS." Tribologia 273, no. 3 (June 30, 2017): 91–100. http://dx.doi.org/10.5604/01.3001.0010.6140.
Full textAbstract:
The paper covers the mechanism of lubrication layer formation by fuels containing synthetic hydrocarbons and alcohols. Development of alternative fuels containing FAME, alcohols, and synthetic hydrocarbons has increased the interest in the mechanism of lubrication of fuelling systems parts. Fuel lubricity tests have been conducted using the HFRR and BOCLE testing rigs. Fuels under testing, both for CI engines and for aviation turbine ones, contained synthetic components: saturated hydrocarbons both of even and odd number of carbon atoms, and butanol, isomers. These components have been added to conventional fuels, such as diesel fuel and Jet A-1 fuel at the concentration of 0–20% (V/V). All fuels under testing contained commercially available lubricity improvers (carboxylic acid). Test results were analysed using model αi described in [L. 6, 7]. As a result of the analysis, it has been found that the liquid phase, which is a lubricating film, should contain agglomerates or molecular clusters responsible for the transport of energy introduced into lubricating film by electrons emitted from metal surface. The mechanism enabling a description of the effect of base fuel without lubricity improvers on efficiency of such additives has been suggested.
10
Rahn, David A., Thomas R. Parish, and David Leon. "Airborne Measurements of Coastal Jet Transition around Point Conception, California." Monthly Weather Review 141, no. 11 (October 25, 2013): 3827–39. http://dx.doi.org/10.1175/mwr-d-13-00030.1.
Full textAbstract:
Abstract Low-level winds along the Californian coast during spring and early summer are typically strong and contained within the cool, well-mixed marine boundary layer (MBL). A temperature inversion separates the MBL from the warmer free troposphere. This setup is often represented by a two-layer shallow-water system with a lateral boundary. Near a prominent point such as Point Conception, California, the fast-moving MBL flow is supercritical and can exhibit distinct features including a compression bulge and an expansion fan. Measurements from the University of Wyoming King Air research aircraft on 19 May 2012 during the Precision Atmospheric MBL Experiment (PreAMBLE) captured wind in excess of 14 m s−1 off of Point Conception under clear skies and wind ~2 m s−1 east of San Miguel in the California Bight. A compression bulge was identified upwind of Point Conception. When the flow rounds the point, the MBL undergoes a near collapse and there is a spike in MBL height embedded in the general decrease of MBL height with greater turbulence just downwind that is associated with greater mixing through the inversion layer. Lidar and in situ measurements reveal that transport of continental aerosol is present near the pronounced MBL height change and that there is a complex vertical structure within the Santa Barbara Channel. Horizontal pressure gradients are obtained by measuring the slope of an isobaric surface. Observations of wind and pressure perturbations are able to be linked through a simple Bernoulli relationship. Variation of MBL depth explains most, but not all of the variation of the isobaric surface.
Dissertations / Theses on the topic "Jet transport container"
1
Похилько, Борис Сергійович. "Реактивний транспортний контейнер." Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/39372.
Full textAbstract:
Пояснювальна записка містить 108 сторінок, в тому числі 61 рисунків,
9 таблиць, 15 джерел. Графічна частина виконана на аркушах формату А1.
В дисертаційному дослідженні запропонована концепція реактивного
транспортного контейнеру, що забезпечує активацію корисного
навантаження у вигляді безпілотного літака на безпечній відстані від
персоналу, який забезпечує експлуатацію безпілотного комплексу.
В дисертаційному дослідженні було розглянуто основні результати
наукових досліджень за напрямком проектування ракетних комплексів із
дозвуковою швидкістю польоту. Визначено вплив параметрів компонування
контейнеру на аеродинамічні характеристики.
З використанням методів обчислюваної аеродинаміки виконано
моделювання обтікання поверхні реактивного транспортного контейнеру,
визначений момент розкриття контейнеру MOPEN та швидкість балансування
VБАЛ. За допомогою наявного програмного забезпечення виконано
моделювання роботи твердопаливного прискорювача, визначений загальний
імпульс IJETта його тривалість в часі. Виконане робоче проектування агрегатів
системи керування реактивного транспортного контейнеру шляхом
відхилення реактивного струменю.
В процесі дослідження використовувалося комп'ютерне моделювання,
сучасне програмне забезпечення, а саме: програми Microsoft Office,
КОМПАС-3D- V18.1, PANSYM, OriginPro 7, CorelDRAW.The explanatory note contains 108 pages, including 61 figures, 9 tables, 15 sources. The graphic part is made on sheets of A1 format. The dissertation research proposes the concept of a jet transport container, which provides activation of the payload in the form of an unmanned aircraft at a safe distance from the personnel who operate the unmanned complex. In the dissertation research the main results of scientific researches in the direction of designing of missile systems with subsonic speed of flight were considered. The influence of container layout parameters on aerodynamic characteristics is determined. Using the methods of calculated aerodynamics, the surface flow of the jet transport container was modeled, the opening moment of the MOPEN container and the balancing speed VBAL were determined. With the help of the available software the simulation of solid fuel accelerator operation is performed, the total impulse of IJET and its duration in time are determined. The working design of the units of the control system of the jet transport container by deflection of the jet is performed. The study used computer simulation, modern software, namely: Microsoft Office, COMPASS-3D-V18.1, PANSYM, OriginPro 7, CorelDRAW.
Books on the topic "Jet transport container"
1
Air pollution: Information contained in EPA's regulatory impact analyses can be made clearer : report to Congressional committees. Washington, D.C: The Office, 1997.
Find full text
2
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
3
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
4
Office, General Accounting. Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to Congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
5
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
6
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
7
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
8
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full text
9
Public-private competitions: DOD's additional support for combining depot workloads contains weaknesses : report to congressional requesters. Washington, D.C. (P.O. Box 37050, Washington, D.C. 20013): The Office, 1998.
Find full textBook chapters on the topic "Jet transport container"
1
V. Nesyn, Georgii. "Activated Flooded Jets and Immiscible Layer Technology Help to Remove and Prevent the Formation of Bottom Sediments in the Oil Storage Tanks." In Sediment Transport - Recent Advances [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95230.
Full textAbstract:
Two flooded jet methods of tank bottom sediments caving based on either screw propeller generation or nozzle jets generated with entering crude head oppose each other. The comparison is not advantageous for the first one. Exceptionally if crude oil contains some concentration of high molecular weight polymer which can perform Drag Reduction. In this case, the jet range increases by many times, thus, upgrading the capability of caving system. Preventing the sedimentation of crude oil heavy components may be put into practice with Immiscible Layer Technology. Before filling the tank with crude oil, some quantity of heavy liquid, that is immiscible with all the components of crude oil, is poured into the tank. The most suitable/fit for purpose and available liquid is glycerin. Neither paraffin and resins, nor asphaltenes can penetrate through the glycerin layer to settle down at the tank bottom because of its density, which is equal to 1.26 g/cm3. Instead, sediments are concentrated at/on the glycerin surface and when it is heated in external heat exchanger all the sediments ought to move upwards with the convection streams. Thus, no deteriorate sediment is formed in the tank bottom.
Conference papers on the topic "Jet transport container"
1
Lee, Xiaobo, Xuefeng Lyu, and Ke Ji. "The Experimental Study on Stratification and Transport of Hydrogen in the Containment With Light Non-Condensable Gas." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66833.
Full textAbstract:
This study was based on the passive containment thermal hydraulic facility, which locating in Beijing Key Laboratory of Passive Nuclear Power Safety and Technology, North China Electric Power University, Beijing. The platform was built in the year of 2010, Pro. Niue has carried out a series of studies about the thermal stratification and concentration stratification for air and water vapour and achieved remarkable results. In this paper, the experimental test is divided into two consecutive stages: phase A and phase B. Phase A is the injection phase of steam, however, phase B is divided into three steps, include hydrogen injection, no injection, opening the external spray, to study the stratification and transport of hydrogen (replaced with helium) in a cylindrical steel container which has ellipsoid dome, and also discussing the change of hydrogen concentration near the wall over time. Except for this, the distribution of hydrogen during the third step is also emphasized. For the transport of gas, it has not given the direct result of measuring in this paper, but it gave the analysis of transport which is based on the hydrogen concentration at different stages, different location of the containment over the time. It can be found that: 1) during the stages of hydrogen injection, no injection, the stratification is obvious, but, the helium concentration in the dome space is uniform, and the transport of the gas is mainly affected by the thermal buoyancy and jet, 2) near the wall-area, the trend of droplet entrainment is obvious, 3) during the stage of opening the external spray, the mixture of gas is intensified and the stratification is weakened.
2
Tyagi, Mayank, and Sumanta Acharya. "Large Eddy Simulations of Jets in Crossflow: Large Scale Turbulence Effects." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0987.
Full textAbstract:
Abstract Large eddy simulations of jets in crossflow are performed to study the effect of energy containing scales present in the freestream on the penetration and spread of the coolant jet. Two specific freestream turbulence conditions are examined, one corresponding to 15% small scale Gaussian turbulence, and the other corresponding to a 15% freestream turbulence that satisfies the Von-Karman spectrum and has its peak energy specified in the small wave number range (large scales). The small-scale freestream turbulence can be viewed to be similar to grid generated turbulence. The large scale freestream turbulence spectrum has energy peak at a small wave number (corresponding to a specified length scale taken to be 4 hole diameters in this study) and has energy in the inertial subrange for large wave numbers. In the present study, the jets are issued through a row of square holes into the main crossflow. The jet to crossflow blowing ratio is 0.5 and the jet Reynolds number is approximately 4,700. Greater jet penetration and jet-mainstream mixing, in both the vertical and lateral directions, are observed for large-scale turbulence. The energy contained in large scales is mostly preserved although the energy carrying scales themselves undergo subsequent breakdown process due to the effect of the jet. In the nearfield of the jet, the large scales play a major role in enhancing the turbulent stresses, and the near wall transport. In the presence of the large scales, the horseshoe vortex is energized, and there is greater crossflow entrainment into the wake region. These large scale effects lead to significantly greater wall friction.
3
Li, Lei, GuoPing Huang, Jie Chen, and JinChun Wang. "Numerical Investigation of Self-Driven Fan Performance With Tip-Jet." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63783.
Full textAbstract:
Tip-jet rotor system has unique potential value in the area of vertical take-off and landing (VTOL) or short take-off and landing (STOL) concept aircraft. The main objective of the current work is to investigate the aerodynamic properties of a self-driven fan with tip-jet (SDF_TJ) in hover by numerical experiments. In order to obtain the detailed flow phenomena of SDF_TJ, CFD method is performed, which is conducted by solving three-dimensional Reynolds-averaged Navier-Stokes equations using the shear stress transport turbulence model. For the purpose of investigation, the analysis of SDF_TJ performances with different nozzle configurations have been carried out. Current results indicate the conformal tip-jet not only provide the reaction torque, but also augment the fan lift via entraining the main flow above the suction surface of blade. The rotation speed of fan is mainly determined by bleed air parameters and nozzle area, so as to torque self-balance. The total torque produced by jets contains rotor required torque and penalty torque induced by Coriolis force. The blade lift coefficient and the ratio with jet momentum coefficient are influenced by the distance from the nozzle downstream edge to blade trailing. As the lift of SDF_TJ is larger than the thrust generated by jets alone, which could benefit the take-off and landing capability of VTOL concept aircraft.
4
Ivanova, Elizaveta, Berthold Noll, and Manfred Aigner. "A Numerical Study on the Turbulent Schmidt Numbers in a Jet in Crossflow." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69294.
Full textAbstract:
This work presents a numerical study on the turbulent Schmidt numbers in jets in crossflow. This study contains two main parts. In the first part the problem of the proper choice of the turbulent Schmidt number in the Reynolds-Averaged Navier-Stokes (RANS) jet in crossflow mixing simulations is outlined. The results of RANS employing the shear-stress transport (SST) model of Menter and its curvature correction modification and different turbulent Schmidt number values are validated against experimental data. The dependence of the “optimal” value of the turbulent Schmidt number on the dynamic RANS model is studied. Furthermore a comparison is made with the large-eddy simulation (LES) results obtained using the WALE (Wall-Adapted Local Eddy Viscosity) model. The accuracy given by LES is superior in comparison to RANS results. This leads to the second part of the current study, in which the time-averaged mean and fluctuating velocity and scalar fields from LES are used for the evaluation of the turbulent viscosities, turbulent scalar diffusivities, and the turbulent Schmidt numbers in a jet in crossflow configuration. The values obtained from the LES data are compared with those given by the RANS modeling. The deviations are discussed and the possible ways for the RANS model improvements are outlined.
5
Taslim, Mohammad E., and Fei Xue. "Experimental/Numerical Investigation of Crossover Jet Impingement in a Rib-Roughened Trailing-Edge Cooling Channel." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56139.
Full textAbstract:
Local and average heat transfer coefficients were measured in a test section simulating a rib-roughened trailing edge cooling cavity of a turbine airfoil. The rig was made up of two adjacent channels, each with a trapezoidal cross sectional area. The first channel supplied the cooling air to the trailing-edge channel through a row of racetrack-shaped slots on the partition wall between the two channels. Eleven cross-over jets, issued from these slots entered the trailing-edge channel, impinged on eleven ribs, made a 90-degree turn and exited from the end of the trailing-edge channel. Tests were run for the baseline case of smooth target wall as well as four angles of attack between the axial flow and the ribs (0°, 45°, 90° and 135°). Cross-over jet axis made a zero-degree angle with the trailing-edge channel center-plane. Jet Reynolds number was varied from 10,000 to 35,000. The numerical models contained the entire trailing-edge and supply channels with all slots and ribs to simulate exactly the tested geometries. They were meshed with all-hexa structured mesh of high near-wall concentration. A pressure-correction based, multi-block, multi-grid, unstructured/adaptive commercial software was used in this investigation. The k–ω with Shear Stress Transport (SST) turbulence model was used for turbulence closure. Boundary conditions identical to those of the experiments were applied and several turbulence model results were compared. The numerical analyses also provided the share of each cross-over hole from the total flow for different rib geometries. The major conclusions of this study were:a) Both measured and numerically-obtained results show that the local Nusselt numbers correlate well with the local jet Reynolds numbers, b) 90° rib arrangement, that is when the cross-over jet axis was parallel to the rib longitudinal axis, produced a higher heat transfer coefficient, and c) Numerical heat transfer results were generally in good agreement with the test results. The overall difference between the CFD and test results was about 10%.
6
Drzewiecki, Timothy J., Brian L. Mount, and Martin Lopez de Bertodano. "Development and Validation of a Porous Medium Computational Fluid Dynamics Model for a Jet." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48798.
Full textAbstract:
The fast boron shutdown injection in a PHWR consists of a jet flowing through a very large moderator tank that contains an array of cylindrical coolant channels. The accurate prediction of the turbulent jet mixing is required to determine an accurate distribution of boron inside the moderator tank to model the insertion of negative reactivity into the reactor during fast shutdown. A CFD code is used to determine the distribution of boron in the moderator tank. The flow is analyzed with a porous medium model based on volume averaged momentum, turbulent kinetic energy, and turbulence dissipation equations. The additional source terms arise due to the averaging must be constituted. The constitutive relations that are implemented in the present model are: (i) the drag force on an array of cylinders for the momentum equations and (ii) the additional mixing effect of the cylinders which results in the sources of turbulent kinetic energy and turbulence dissipation transport model. The CFD analysis is performed on a porous, axis symmetric domain. The CFD results are finally compared with data for the boron concentration distribution obtained in a scaled geometrically similar experiment, demonstrating the validity of the approach.
7
Aleyasin, Seyed Sobhan, Nima Fathi, Mark Francis Tachie, and Mikhail Koupriyanov. "Comparison of Turbulent Jets Issuing From Various Sharp Contoured Nozzles." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69419.
Full textAbstract:
An experimental study was conducted to investigate nozzle geometry effects on mixing characteristics and turbulent transport phenomena in the near and intermediate regions of free jets issuing from modified contoured nozzles (contoured nozzle with a sharp linear contraction). The cross-sections examined were round, square, equilateral triangle as well as ellipse and rectangle with aspect ratio of 2. For each nozzle shape, detailed velocity measurements were made using particle image velocimetry at a Reynolds number of 10000. It was observed that noncircular jets have shorter potential cores than their round counterparts and their lengths are comparable with those of orifice jets. In addition, the spread and decay rates and the levels of turbulence intensities are the highest in the jets issuing from the elliptic and rectangular nozzles, implying enhanced mixing in these jets. The results from the swirling strength analysis revealed that the rotational motions induced by vortices within the minor planes of the elliptic and rectangular jets are more intense than those observed in the other jets. Furthermore the obtained data indicate distinctly different flow characteristics in the major and minor planes of elliptic, rectangular and triangular jets due to their asymmetric shapes. The size of turbulence structures in all the jets studied increases with streamwise distance and the elliptic and rectangular jets contain the largest structures.
8
Naik, Chitralkumar V., Karthik V. Puduppakkam, and Ellen Meeks. "An Improved Core Reaction Mechanism for Saturated C0–C4 Fuels." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46705.
Full textAbstract:
Accurate chemistry models are required to predict the combustion behavior of different fuels, such as synthetic gaseous fuels and liquid jet fuels. A detailed reaction mechanism contains chemistry for all the molecular components in the fuel or its surrogates. Validation studies that compare model predictions with the data from fundamental combustion experiments under well defined conditions. Such fundamental experiments are least affected by the effect of transport on chemistry. Therefore they are the most reliable means for determining a reaction mechanism’s predictive capabilities. Following extensive validation studies and analysis of detailed reaction mechanisms for a wide range of hydrocarbon components reported in our previously published work [1–5], we identified some common issues in the predictive nature of the mechanisms that are associated with inadequacies of the core (C0–C4) mechanism. For example predictions of laminar flame speeds and autoignition delay times for several fuels were inaccurate beyond the level of uncertainty in the data. This core mechanism is shared by all of the mechanisms for the larger hydrocarbon components. Unlike the reaction paths for larger hydrocarbon fuels, however, reaction paths for the core chemistry do not follow prescribed reaction rate-rules. In this work, we revisit our core reaction mechanism for saturated C0–C4 fuels, with the goal of improving predictions for the widest range of fundamental experiments as possible. To evaluate and validate the mechanism improvements, we performed a broad set of simulations of fundamental experiments. These experiments include measurements of ignition delay, flame speed and extinction strain rate, as well as species composition in stirred reactors, flames and flow reactors. The range of conditions covers low to high temperatures, very lean to very rich fuel-air ratios, and low to high pressures. Our core reaction mechanism contains thermochemical parameters derived from a wide variety of sources, including experimental measurements, ab initio calculations, estimation methods and systematic optimization studies. Each technique has its uncertainties and potential inaccuracies. Using a systematic approach that includes sensitivity analysis, reaction-path analysis, consideration of recent literature studies, and an attention to data consistency, we have identified key updates required for the core mechanism. These updates resulted in accurate predictions for various saturated fuels when compared to the data over a broad range of conditions. All reaction rate constants and species thermodynamics and transport parameters remain within known uncertainties and within physically reasonable bounds. Unlike most mechanisms in the literature, the mechanism developed in this work is self-consistent and contains chemistry of all saturated C0–C4 fuels.
9
Dombrovsky, Leonid A., and Mikhail V. Davydov. "Thermal Radiation From the Zone of Melt-Water Interaction: Computational Model and Some Numerical Results." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22157.
Full textAbstract:
This paper is concerned with numerical modeling of thermal radiation from the zone of interaction of a melt jet with a water pool. This particular problem is a part of the analysis of complex interaction of the core melt with water in the case of a hypothetical severe accident in light-water nuclear reactors. The energetic contribution of thermal radiation has been studied in some details in recent papers by the authors. In the present paper, we focus on a solution related with possible optical diagnostics of the physical parameters of the process. This diagnostics can be based on comparison of the measured and calculated thermal radiation in the small-scale laboratory experiments. The sensitivity of the numerical data to some important parameters of the computational model is expected to be important to validate and improve the multiphase flow model. The radiation transfer model employed is based on the transport approximation. The numerical procedure includes ray-tracing calculations in the range of water semi-transparency with a source function determined using the large-cell radiation model. It is shown that the visible radiation of the interaction zone contains important information on the process parameters and these parameters might be identified on the basis of the developed computational procedure for the direct problem.
10
Qi, Aisha, James R. Friend, and Leslie Y. Yeo. "Inhaled Pulmonary Drug Delivery Platform Using Surface Acoustic Wave Atomization." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18516.
Full textAbstract:
Atomization has been widely applied in pulmonary drug delivery as a promising technology to transport drug formulations directly to the respiratory tract in the form of inhaled particles or droplets. Because of the targeted treatment, the drug can be delivered directly to the site of inflammation, thus the need for systemic exposure and the possibility of side effects are both reduced. Therefore pulmonary drug delivery has significant advantages over other methods in the treatment of respiratory diseases such as asthma. The most common atomization methods employed in pulmonary drug delivery are jet atomization and ultrasonic atomization. However, the difficulty is in producing monodispersed particles/droplets in a size range of 1–5 micron meter in diameter, necessary for deposition in the targeted lung area or lower respiratory airways, within a controllable fashion. In this paper, we demonstrate surface acoustic wave (SAW) atomization as an efficient technique to generate monodispersed aerosol to produce the required size distribution. The SAW atomizer is made of a 127.86 Y-X rotated single-crystal lithium niobate piezoelectric substrate, which is patterned with chromium-aluminum interdigital transducer (IDT) electrodes via UV lithography. When an alternating electric field is applied onto lithium niobate substrate through the IDT, a SAW, propagating across substrate surface with ten nanometer order amplitudes, is generated. When the SAW meets the liquid which is placed upon substrate, the acoustic energy carried by the wave induces atomization of the working fluid, which contains salbutamol as a model drug. In order to measure the size distribution of the atomized droplets, two methods are used. One is the laser diffraction based Spraytec technique and the other is an in-vitro lung modelthe one stage glass twin impinger. The former revealed that the mean diameter of the aerosol atomized was around 3 um which were confirmed by the lung model that demonstrated that nearly 80% of atomized drug aerosol was deposited in the simulated lung area. Moreover, the SAW atomizer only requires 1–3 W driving power, suggesting that it can be miniaturized for portable consumer use.