Dissertations / Theses on the topic 'Total pressure and total temperature measurement'

This thesis work was performed as a collaboration between the Royal Institute of Technology in Stockholm and Siemens Industrial Turbomachinery in Finspång. It was undertaken with the purpose of investigating the use of CFD methods in ANSYS CFX to predict flow mixing in gas turbines. The results were evaluated against experimental data gathered as part of an international collaboration; The FACTOR project. The experimental data investigated were total temperature and total pressure at nozzle guide vane inlet and outlet. The results thus focus mainly on nozzle guide vane inlet and outlet due to the nature of the available experimental data. The distribution of these parameters was also investigated in the NGV flow channel and on the vane surface, but it is appreciated that any conclusions drawn from these results are speculative in nature due to the lack of experimental data. Any conclusions drawn must be placed in perspective of the evaluation of NGV inlet and outlet, for which experimental data is available. The focus was on the mixing of the total temperature and total pressure in a nozzle guide vane connected to a combustion chamber simulator. The methods investigated were RANS-SST, SBES and LES-WALE. The main conclusions are that the inclusion of a combustion chamber mesh and thus simulating the CC flow increases the accuracy of the nozzle guide vane results for RANS-SST simulations. It is also observed that in general the SBES and LES-WALE method yield highly similar results under the investigated circumstances, and that both these methods show a general improvement over the RANS-SST method.
Detta examensarbete utfördes som ett samarbete mellan KTH i stockholm och Siemen Industrial Turbomachinery i Finspång. Det undertogs med syftet att undersöka användning av CFD-metoder i ANSYS CFX för att förutspå flödesmixning i gasturbiner. Resultaten utvärderades mot experimentel data som samlats genom ett internationellt samarbete: FACTORprojektet. Den experimentella data som undersökts var totaltemperatur och totaltryck vid in- och utloppet till ett statorblad. Resultaten fokuserar huvudsakligen vid in- och utlopp till statorbladed på grund av den tillgängliga experimentella datan. Distributionen av totaltemperatur och totaltryck mellan dessa plan undersöktes också, men det måste lyftas att alla slutsatser som dras av dessa resultat är till någon grad spekulativ på grund av tillgängliga datans natur. Alla slutsatser som dras härutav måste utvärderas i samband med den tillgängliga datan. Det huvudsakliga focuser låg vid mixningen av totaltemperature och totaltryck i ett statorbland anslutet till en brännkammarsimulator. De undersöka metoderna var RANS-SST, SBES och LES-WALE. De huvudsakliga slutsatserna är att inkluderandet av en brännkammar-mesh och därmed simuleringen av brännkammarflödet förbättrar kvaliten på resultatet för statorbladen för RANS-SST simuleringar. Det har också framkommit att SBES och LES-WALE-metoderna resulterar i högst likvärda resultat i de undersökta omständigheterna, och att båda dessa metoder ger ett generellt förbättrat resultat vid jämförelse med RANSSST.

This thesis presents the use of an unsteady total pressure measurement to detect laminar-to-turbulent transition. A miniature dynamic pressure transducer, Kulite model XCS-062-5D, was utilized to measure the total pressure fluctuations, and was integrated with an autonomous boundary layer measurement device that can withstand flight test conditions. Various sensor-probe configurations of the Kulite pressure transducer were first examined in a wind tunnel with a 0.610 m (2.0 ft) square test section with a maximum operational velocity of 49.2 m/s (110 mph), corresponding dynamic pressure of 1.44 kPa (30 psf). The Kulite sensor was placed on an elliptical nose flat plate where the flow was known to be turbulent. The Kulite sensor was then evaluated to measure total pressure fluctuations in laminar, turbulent, and transition of boundary layers developed on the flat plate in the same wind tunnel. The root-mean-square value of total pressure fluctuations was less than 1 % of the local free-stream dynamic pressure in the laminar boundary layer, but was about 2 % in the turbulent boundary layer. The value increased to 4 % in transition, indicating that the total pressure fluctuation measurements can be used not only to distinguish the laminar boundary layer from the turbulent boundary layer, but also to identify the transition region. The unsteady total pressure measurement was also conducted in a with a 2.13 m (7.0 ft) by 3.05 m (10.0 ft) section with similar operational velocity range as the previous wind tunnel. The Kulite sensor was placed on a wing model under laminar and transition conditions. The testing yielded similar results, demonstrating the usefulness of total pressure measurement for identifying the laminar-to-turbulent transition.

Distortion tolerant fans represent the enabling technology for the successful implementation of highly integrated airframe propulsion system vehicles. This investigation extends the study of fan-distortion interactions to an actual turbofan engine with a total pressure distortion profile representative of a boundary-layer ingesting (BLI) embedded engine. The goal was to make a series of flow measurements that contribute to the overall physical understanding of this complex flow situation. Proper uncertainty analysis is critical to extracting meaning from the data measured in this study. The important information in the measurements is contained in small differences that lead to large impacts on the fan performance. In some cases, these differences were measured to a useful degree of accuracy, while in others they were not. One important application of the uncertainty analysis techniques developed in this work is the identification of the dominant error sources that resulted in unacceptable uncertainties. This dissertation presents an experimental study of transonic fan response to inlet total pressure distortion. A Pratt and Whitney JT15D-1 turbofan engine was subjected to a total pressure distortion representative of a boundary layer ingesting serpentine inlet. A 5-hole probe measured the aerodynamic response of the fan rotor in terms of flow angles, total pressure, and static pressure. A thermocouple embedded in the probe measured the rotor outlet total temperature. These measurements enabled the full characterization of the flow condition at each measurement point. The results indicate that a trailing edge separation and reattachment cycle experienced by the blades caused variations in the work input to the flow and resulted in a non-uniform rotor outlet flow profile. The details of the aerodynamic process and several means for improving distortion response are presented in this context. As a second theme, the modern measurement and uncertainty analysis techniques required to obtain useful information in this situation are developed and explored. Uncertainty analysis is often treated as a less glamorous afterthought in experimental research. However, as technology develops along lines of ever increasing system-level integration, simply suggesting the solution to a single flow situation does not repre- sent closure to the larger problem. In addition to frameworks for developing distortion tolerant fans, frameworks for developing frameworks are required. Uncertainty-drivenexperimental techniques represent the enabling methodology for the discovery and un- derstanding of the subtle phenomena associated with such coupled performance. These considerations are required to extend the usefulness of the results to the overarching issue of integrating the complex performance of individual components into an overall superior system. The experimental methods and uncertainty analysis developed in this study are presented in this context.
Ph. D.

A non-invasive, in vitro method of estimating mean pulmonary artery pressure (PAP) was developed. This information was obtained by establishing a relationship between the pneumatic right drive pressure (RDP) and PAP waveforms. The RDP-PAP relationship was formalized into a series of multiple-linear regression equations for TAH cardiac cycles of known fill volume (FV). Correlation of computed estimates of PAP to actual measurements showed that these equations were greater than 92% accurate within 1.84 mmHg. In addition, while the RDP-PAP relationships were wholly dependent on FV, it was shown that they are independent of the manner in which FV was obtained. This method proved useful over the clinical operating range of the pneumatic heart driver, as well as over the normal physiological range of PAP in the human. Effectiveness of this method in vivo needs to be demonstrated.

High blood pressure (BP) is the most significant risk factor for cardiovascular disease and a major contributor to chronic disease burden in the United States. Chronic conditions are the most common reason for office-based physician visits among adults, accounting for 37% of all visits. Home BP monitoring when combined with clinical support may help engagement with care and improve condition control. This study examines the extent to which home BP measurement is associated with total office visits among Medicare beneficiaries with self-reported high BP and the influence by other related factors. The 2018 Medicare Current Beneficiary Survey (MCBS) was used in the study. The study population consists of Medicare beneficiaries (n=4,456) with self-reported high BP who had at least one total office visit in the year. Total office visits served as the outcome and were dichotomized to low (1-5 visits) and high (greater than 5 visits), while self-reported home BP measurement was the primary independent variable. Andersen’s conceptual framework was used to establish the co-variates [Predisposing factors: age, gender, race, education; Enabling factors: insurance plan (Medicare Advantage, MA), income, patients’ satisfaction (a. quality, b. information); Individual needs: smoking, BMI; Environment: region]. Bivariate analysis using a chi-square test for independence, unadjusted and adjusted logistic regression was conducted using SAS v 9.4. Of the study population, 57.9% reported measuring blood pressure at home. Approximately 95.6% and 94.2% of beneficiaries were satisfied with the quality of care received and information about their symptoms respectively. Bivariate analysis showed a significant relationship between total office visits and home BP measurement (p<0.05). Unadjusted logistic regression results noted that those who reported home BP measurement had increased odds of high total office visits [uOR: 1.17 (1.02-1.33)]. This relationship was slightly increased in the adjusted analysis when accounting for other factors of interest [aOR:1.22 (1.06- 1.40)]. Those aged 65-74 years had reduced odds [aOR: 0.77 (0.61 -0.98)], females had increased odds [aOR: 1.38 (1.19 – 1.61)], and those with higher education had increased odds [aOR: 1.41 (1.14 -1.75)] of high total office visits. Those not enrolled in MA [aOR: 3.37 (2.31- 4.90)] and those who earn $25,000 or more [aOR: 1.23 (1.04 -1.45)] had increased odds of high total office visits. Those who have never smoked [aOR: 0.81 (0.69-0.94)] and those from the non-metro region [aOR: 0.65 (0.56-0.76)] had reduced odds of high total office visits. We conclude that those who engage in home BP monitoring are more likely to have a high number of total office visits. The use of home BP monitoring could reflect the severity of high BP suggesting the need for regular follow-up and frequent use of services. Further studies that explore this association are recommended.

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica
Since mercury thermometers were banned due to environmental concerns, hospitals started to use electronic thermometers for measuring body temperature. Body temperature can be measured from different body parts, although the least invasive and quickest is preferred and therefore eardrum measurements are frequently taken. However, lately the staff feels that the taken measurements are not accurate. A new purchasing agreement for the purchase of these devices renders a good opportunity to study further the use of these devices at the wards of the university hospital, study their maintenance process, identify what performance is essential for the clinical usage, the parameters that are essential to measure and also identify ear thermometers in the market that can be used for comparative study. Temperature measurements were taken with the help of an infrared ear thermometer, Covidien Genius2, in its calibration blackbody device at the R&D department of the Huddinge Hospital in order to verify accuracy claims. This data were compared against other studies and measurements of other infrared ear thermometers devices, the Braun ThermoScan Pro 4000 and also a digital contact thermometer, Welch Allyn Suretemp Plus, applied to different body sites. Informal meetings also took place in order to get more information about the devices and to know where they were used and repaired. It was found that Genius2 measured temperature accurately when compared with a blackbody radiator. Regarding the Braun, it showed an accurate estimate of core temperature in comparison to invasive pulmonary artery catheter thermometry. Electronic tympanic thermometers proved to be a good replacement for conventional methods of thermometry. However, preventive maintenance should occur more often, since the devices are very fragile. Tympanic thermometers are generally very accurate instruments. Most likely, problems are not related to the thermometers themselves, they are possibly the result of an inadequate understanding of the limitations of ear thermometry.

The traditional radiation testing of space electronics has been used for more than fifty years to support the radiation hardness assurance. Its typical goal is to ensure reliable operation of the spacecraft in the harsh environment of space. This PhD research looks into the radiation testing from a different perspective; the goal is to develop radiation testing methods that are focused not only on the reliability of the components but also on a continuous radiation-induced degradation of their performance. Such data are crucial for the understanding of the impact of radiation on the measurement uncertainty of data acquisition systems onboard research space missions.

The master’s thesis deals with ways of controlling starting clutches of cars, especially of DQ200 gearbox, which contains dry disc clutches. The introduction describes basic principles of torque transfer and amount of clutch force. Then the description of construction of starting clutches and ways of controlling clutch types mentioned beforehand is given. In the next part of the thesis, wide spectrum of control methods is measured, from which a certain part is selected. This is followed by driving tests and based on driving data, one method of the clutch control is chosen. Then those control methods from narrow selection are tested for acoustic impact in the cabin of the car. In the end the best way of clutch control is selected. The selection based on driving data and acoustic measurement.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 – електричні станції, мережі і системи – Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", Київ, 2018. Дисертація присвячена науково-прикладній проблемі – пошуку винуватців гармонічних спотворень в електричних мережах та підвищенню якості електроенергії шляхом створення системи діагностики і контролю на базі АСКОЕ. Обґрунтовано використання технології розподілених вимірювань для пошуку винуватців спотворень. Розроблено модифікацію методу гармонічного аналізу для підвищення достовірності визначення джерел спотворення. На підставі результатів досліджень запропоновано методи розподілу компенсаційних виплат між елементами електричної мережі та абонентами, що споживають потужність вищих гармонік. Розроблено ряд рекомендацій щодо практичного застосування результатів дисертаційної роботи. Запропоновано метод непрямого контролю температури кабельних ліній.
Thesis for the PhD degree in technical sciences, Specialty 05.14.02 – power plants and electric power complexes. National technical university of Ukraine "Kyiv polytechnic institute", Kyiv, 2019. The thesis is oriented to the scientific and applied problem - harmonic distortion sources detection in distribution systems (DS), improving the electromagnetic compatibility of electrical equipment, increasing the reliability of electric power supply by creating a diagnostic and control system. The use of distributed measurements to distortions source detection is justified. A modification of the method of harmonic analysis is developed to increase the reliability of distortions sources detection. Based on the study’s results, methods for distributing compensation payments between DS`s subjects that consume harmonics power are proposed. A number of recommendations on the practical application of the results of the thesis work have been developed. A method for indirect monitoring of the temperature of cable lines is proposed.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 – електричні станції, мережі і системи – Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", Київ, 2018. Дисертація присвячена науково-прикладній проблемі – пошуку винуватців гармонічних спотворень в електричних мережах та підвищенню якості електроенергії шляхом створення системи діагностики і контролю на базі АСКОЕ. Обґрунтовано використання технології розподілених вимірювань для пошуку винуватців спотворень. Розроблено модифікацію методу гармонічного аналізу для підвищення достовірності визначення джерел спотворення. На підставі результатів досліджень запропоновано методи розподілу компенсаційних виплат між елементами електричної мережі та абонентами, що споживають потужність вищих гармонік. Розроблено ряд рекомендацій щодо практичного застосування результатів дисертаційної роботи. Запропоновано метод непрямого контролю температури кабельних ліній.
Thesis for the PhD degree in technical sciences, Specialty 05.14.02 – power plants and electric power complexes. National technical university of Ukraine "Kyiv polytechnic institute", Kyiv, 2019. The thesis is oriented to the scientific and applied problem - harmonic distortion sources detection in distribution systems (DS), improving the electromagnetic compatibility of electrical equipment, increasing the reliability of electric power supply by creating a diagnostic and control system. The use of distributed measurements to distortions source detection is justified. A modification of the method of harmonic analysis is developed to increase the reliability of distortions sources detection. Based on the study’s results, methods for distributing compensation payments between DS`s subjects that consume harmonics power are proposed. A number of recommendations on the practical application of the results of the thesis work have been developed. A method for indirect monitoring of the temperature of cable lines is proposed.

Subsea compression is becoming an important technology in the exploitation of natural gas resources, especially in the North Sea. The well stream is typically a mixture of hydrocarbon gases, liquids and water, with a liquid content up to 5% in volume. The wet flow can be processed with liquid/gas separators before its compression, or compressed as it is. The use of separators or scrubbers, which is possible in most land based applications, becomes exceedingly expensive for subsea applications. For this reason, technology for wet gas compression is currently being developed. Several studies focus on the development of such compressors, but low attention is paid to the measurement technologies and test accuracy. Performance tests on these machines involve the measurement of several parameters, which is usually performed by standard probes. This is not recommended in a wet environment, where the droplets can come in contact with the sensing element of the sensors and considerably perturb the measurement. For this reason, wet tolerant probes are a fundamental issue in order to execute reliable measurements. The objective of the present work is the development of a validated methodology for the design and characterization of wet tolerant probes for the measurement of total pressure and total temperature of gas phase in wet conditions. Starting from a literature search, some conceptual designs of probe were developed, together with an analytical model for their detailed design. The model is based on the specific application operating conditions and on a first attempt geometry. It provides a complete analysis of probes performance, from the fluid dynamics and the structural point of view. After the first iteration, the user can change the value of the design parameters, until the required performance is reached. The developed tool aims to become a reliable instrument for wet tolerant probes design. For this reason, it requires a validation. The model was used to design probes for a real case, which consisted in a pressurized two phase flow composed by air and water, with a liquid content up to 3% in volume. From the structural point of view, probes reduced size and the high stress deriving from the interaction with the droplets lead to two calculation steps: first, a calculation was done applying traditional engineering sizing rules on a simplified probe assembly model; then, a 3-D Finite Element Analysis (FEA) was carried out to validate the model. As expected, the results of the numerical analysis confirmed those of the analytical model, in terms of mechanical stress and natural frequencies. The design obtained with the model was then used to manufacture some probe prototypes, using a Direct Metal Laser Sintering (DMLS) technique. After manufacturing, some ping tests were performed on probes, in order to estimate their first natural frequencies. The results of these tests confirmed those obtained with the numerical analyses, with percentage relative errors on the first natural frequencies lower than 2.0%. After this step, some preliminary performance tests were run in dry conditions, in the aerodynamic facility of GE Oil & Gas (Florence). A good agreement between analytical and experimental data was obtained in terms of recovery factor, especially for total pressure probes. The results of tests in dry conditions are not sufficient to validate the probes in a wet environment: to this end, tests were also run in wet conditions, in a facility located at Southwest Research Institute (SwRI, Texas). The results showed a certain agreement between analytical and experimental results, even though the test rig was not specifically designed for probes validation and the test conditions were not suitable for getting all the needed information. The measurement uncertainty also affected the results. For this reason, a dedicated test rig for an accurate wet probes validation is currently under development. The testing and post processing activities were followed by a study on technologies for the improvement and miniaturization of probes. A specific research was conducted on super-hydrophobic materials for industrial applications. These materials represent an important way to improve and miniaturize probes, which again should require experimental tests. The dedicated test rig will be an useful instrument for the validation of probes and the investigation of new solutions to improve their design.

Biocompatible sensors have been demonstrated using traditional microfabrication techniques modified for polymer substrates and utilize only materials suitable for implantation or bodily contact. Sensor arrays for the measurement of the load condition of polyethylene spacers in the total knee arthroplasty (TKA) prosthesis have been developed. Arrays of capacitive sensors are used to determine the three-dimensional strain within the polyethylene prosthesis component. Data from these sensors can be used to give researchers a better understanding of component motion, loading, and wear phenomena for a large range of activities. This dissertation demonstrates both analytically and experimentally the fabrication of these sensor arrays using biocompatible polymer substrates and dielectrics while preserving industry-standard microfabrication processing for micron-level resolution. An array of sensors for real-time measurement of pressure profiles is the long-term goal of this research. A custom design using capacitive-based sensors is an excellent selection for such measurement, giving high spatial resolution across the sensing surface and high load resolution for pressures applied normal to that surface while operating at low power.

碩士
清雲科技大學
電子工程所
98
This thesis is based on the frustrated total internal reflection and the use of prism-coupled Kretschmann configuration to the surface plasma wave stimulation. Because the water has different dielectric constants at various frequencies, which can be used to stimulate the surface of plasma waves to identify the different water at various frequencies and the depth of absorption sensitively. Th is research is using three-layer formula to do the computer simulation. The computer simulation first focuses on water of different frequencies to analyze and compare and changes the configuration of the Kretschmann metallic film thickness to observe its difference. During the tests of rays designs we first used the helium neon laser assigns out the parallel light to stimulate the surface of plasma wave’s incident photo source and used the revolving platform to change the angle of incident light injection, which will affect the intensity size of the reflected light. Finally we used computer to save the variation data of reflected light''s intensity to the analysis and the research.