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Research of the influence of the gas flow temperature field irregularity in the gas turbine engine combustion chamber outlet on the integral characteristics of the flow and its results averaging ИССЛЕДОВАНИЕ ВЛИЯНИЯ НЕРАВНОМЕРНОСТИ ПОЛЯ ТЕМПЕРАТУРЫ ГАЗОВОГО ПОТОКА НА ВЫХОДЕ ИЗ КАМЕРЫ СГОРАНИЯ ГТД НА  [cached]
В. М. Кофман
Vestnik UGATU , 2012,
Abstract: The influence of the irregularity of the field of temperature total of the gas flow at the outlet of the GTE’s combustion chamber on the integral characteristics of the flow and the results of averaging its parameters were investigated with the help of the developed algorithms of averaging the irregular gas flows and the proper computer program. The most well-grounded way of averaging parameters of gas flow has been found to assess the efficiency of combustion chambers and the gas turbines parameters based on the results of the tests. С помощью разработанных алгоритмов осреднения параметров неравномерных газовых потоков и соответствующей программы для ЭВМ исследовано влияние неравномерности поля температуры торможения газового потока на выходе из камеры сгорания ГТД на интегральные характеристики потока и результаты осреднения его параметров. Установлен наиболее обоснованный способ осреднения параметров газового потока для оценки показателей эффективности работы камер сгорания и турбин ГТД по результатам их испытаний.
A MEMS-Based Flow Rate and Flow Direction Sensing Platform with Integrated Temperature Compensation Scheme  [PDF]
Rong-Hua Ma,Dung-An Wang,Tzu-Han Hsueh,Chia-Yen Lee
Sensors , 2009, DOI: 10.3390/s90705460
Abstract: This study develops a MEMS-based low-cost sensing platform for sensing gas flow rate and flow direction comprising four silicon nitride cantilever beams arranged in a cross-form configuration, a circular hot-wire flow meter suspended on a silicon nitride membrane, and an integrated resistive temperature detector (RTD). In the proposed device, the flow rate is inversely derived from the change in the resistance signal of the flow meter when exposed to the sensed air stream. To compensate for the effects of the ambient temperature on the accuracy of the flow rate measurements, the output signal from the flow meter is compensated using the resistance signal generated by the RTD. As air travels over the surface of the cross-form cantilever structure, the upstream cantilevers are deflected in the downward direction, while the downstream cantilevers are deflected in the upward direction. The deflection of the cantilever beams causes a corresponding change in the resistive signals of the piezoresistors patterned on their upper surfaces. The amount by which each beam deflects depends on both the flow rate and the orientation of the beam relative to the direction of the gas flow. Thus, following an appropriate compensation by the temperature-corrected flow rate, the gas flow direction can be determined through a suitable manipulation of the output signals of the four piezoresistors. The experimental results have confirmed that the resulting variation in the output signals of the integrated sensors can be used to determine not only the ambient temperature and the velocity of the air flow, but also its direction relative to the sensor with an accuracy of ± 7.5o error.
Paleoclimatic reconstructions in western Canada from boreholetemperature logs: surface air temperature forcing and groundwater flow
J. Majorowicz, S. E. Grasby, G. Ferguson, J. Safanda,W. Skinner
Climate of the Past (CP) & Discussions (CPD) , 2006,
Abstract: Modelling of surface temperature change effect on temperature vs.~depth and temperature-depth logs in Western Canada Sedimentary Basin show that SAT (surface air temperature) forcing is the main driving factor for the underground temperature changes diffusing with depth. It supports the validity of the basic hypothesis of borehole temperature paleoclimatology, namely that the ground surface temperature is systematically coupled with the air temperature in the longer term (decades, centuries). While the highest groundwater recharge rate used in the modelling suggests that for this extreme case some of the observed curvature in the profile, could be due to groundwater flow, it is more likely that the low recharge rates in this semi-arid region would have minimal impact. We conclude that surface temperature forcing is responsible for most of the observed anomalous temperature profile.
IMPACTS OF DRYING AIR TEMPERATURE, BED DEPTH AND AIR FLOW RATE ON WALNUT DRYING RATE IN AN INDIRECT SOLAR DRYER
Ghatrehsamani S.H. and Zomorodian A.
International Journal of Agriculture Sciences , 2012,
Abstract: Walnut is one of the world's top 20 agricultural products and is consumed mostly as dried [3]. This product must be dried with great care to maintain its quality. Walnut products are traditionally spread on open space for a long time to reduce the kernel moisture content to a safe level. Due to direct sun radiation and some environmental impacts such as long time exposure the quality of the products may be degraded. Application of renewable energy such as solar energy may be an appropriate substitution for traditional methods.In this research a new pilot size walnut indirect solar batch type dryer was designed and fabricated. The effect of crucial factors affecting drying time namely: drying air temperature (T1:37o C; T2:39o C and T3:41oC), drying air flow rate (F1: 0.065 m3/s, F2: 0.075 m3/s, F3: 0.09 m3/s) and bed depth (D1: 2 layers, D2: 4 layers and D3: 6 layers) were evaluated. The experimental results showed that, the effect of above factors on walnut moisture loss are significant. With increasing drying air temperature, drying air flow rate and number of layers, the amount of average moisture loss decreased from 37% (d.b) to 9% (d.b) at 3 hrs. Performance of dryer was determined at temperature 41oC, air flow 0.09m3/s, 2 layers depth.
The Effects of Mass Flow Rate in an Indirect Ultra-High Temperature Processing System
T.H. Varzakas,A.E. Labropoulos
American Journal of Food Technology , 2007,
Abstract: The effect of mass flow rate on product temperature and residence time were studied in a helically coiled, indirectly steam-heated, vertical flow, laboratory Ultra High Temperature (UHT) system equipped with automatic temperature control and recording units. With a mass flow rate of 0.54 to 3.03 kg min- 1, the Reynolds number (Re) values ranged from 1,500 to 128,000 in the various sections using water as the test product. Holding times were calculated on the basis of holding tube length and velocity. A computer program was applied to predict the temperatures of the product as a function of residence time for the preheating, heating, precooling and cooling heat exchange sections of the UHT unit.
Exchange Flow Rate Measurement Technique in Density Different Gases
Motoo Fumizawa,Shuhei Ohkawa,Isaku Buma,Suguru Tanaka
Journal of Systemics, Cybernetics and Informatics , 2012,
Abstract: Buoyancy-driven exchange flows of helium-air through inclined a narrow tube was investigated. Exchange flows may occur following the opening of a window for ventilation, as well as when a pipe ruptures in a high temperature gas-cooled reactor. The experiment in this paper was carried out in a test chamber filled with helium and the flow was visualized using the smoke wire method. A high-speed camera recorded the flow behavior. The image of the flow was transferred to digital data, and the slow flow velocity, i.e. micro flow rate was measured by PIV software. Numerical simulation was carried out by the code of moving particle method with Lagrange method.
Theoretical relation between water flow rate in a vertical fracture and rock temperature in the surrounding massif  [PDF]
Jean-Christophe Maréchal,Pierre Perrochet
Physics , 2010, DOI: 10.1016/S0012-821X(01)00551-9
Abstract: A steady-state analytical solution is given describing the temperature distribution in a homogeneous massif perturbed by cold water flow through a discrete vertical fracture. A relation is derived to express the flow rate in the fracture as a function of the temperature measured in the surrounding rock. These mathematical results can be useful for tunnel drilling as it approaches a vertical cold water bearing structure that induces a thermal anomaly in the surrounding massif. During the tunnel drilling, by monitoring this anomaly along the tunnel axis one can quantify the flow rate in the discontinuity ahead before intersecting the fracture. The cases of the Simplon, Mont Blanc and Gotthard tunnels (Alps) are handled with this approach which shows very good agreement between observed temperatures and the theoretical trend. The flow rates before drilling of the tunnel predicted with the theoretical solution are similar in the Mont Blanc and Simplon cases, as well as the flow rates observed during the drilling. However, the absence of information on hydraulic gradients (before and during drilling) and on fracture specific storage prevents direct predictions of discharge rates in the tunnel.
A Study into Blood Flow, Heart Rate Variability, and Body Surface Temperature While Listening to Music  [PDF]
Kenichi Itao, Makoto Komazawa, Hiroyuki Kobayashi
Health (Health) , 2018, DOI: 10.4236/health.2018.102015
Abstract: In this study we examined the relaxing effects of listening to music on a total of 12 women aged from their 20s to their 40s by measuring their blood flow, heart rate variability, and their body surface temperature. As a result, We found that there was a tendency for the volume of blood flow to the fingertips to significantly increase when listening to classical music, but there was a variety of changes in blood flow between each age group for healing music and J-Pop music. When measuring heart rate it was found that the LF/HF value, which is an index for the autonomic nervous system which shows tension and stress, fell significantly when listening to each type of music. Lastly, there was a trend for body surface temperature to rise when listening to classical or healing music, a rise which was particularly significant when listening to healing music. This study shows that a relaxing effect can be expected for all indices when listening to classical music. However, for healing music and J-Pop, personal musical preferences seemed to have an effect and the results were varied.
An evaluation of plastic flow stress models for the simulation of high-temperature and high-strain-rate deformation of metals  [PDF]
Biswajit Banerjee
Physics , 2005, DOI: 10.1016/j.actamat.2010.09.009
Abstract: Phenomenological plastic flow stress models are used extensively in the simulation of large deformations of metals at high strain-rates and high temperatures. Several such models exist and it is difficult to determine the applicability of any single model to the particular problem at hand. Ideally, the models are based on the underlying (subgrid) physics and therefore do not need to be recalibrated for every regime of application. In this work we compare the Johnson-Cook, Steinberg-Cochran-Guinan-Lund, Zerilli-Armstrong, Mechanical Threshold Stress, and Preston-Tonks-Wallace plasticity models. We use OFHC copper as the comparison material because it is well characterized. First, we determine parameters for the specific heat model, the equation of state, shear modulus models, and melt temperature models. These models are evaluated and their range of applicability is identified. We then compare the flow stresses predicted by the five flow stress models with experimental data for annealed OFHC copper and quantify modeling errors. Next, Taylor impact tests are simulated, comparison metrics are identified, and the flow stress models are evaluated on the basis of these metrics. The material point method is used for these computations. We observe that the all the models are quite accurate at low temperatures and any of these models could be used in simulations. However, at high temperatures and under high-strain-rate conditions, their accuracy can vary significantly.
Software Visualization of Porous Media with Emphasis on Mass Flow Rate Determinaton as Temperature Changes  [cached]
Olagunju Mukaila,J.S Sadik
Journal of Asian Scientific Research , 2012,
Abstract: Background: Software development has been in existence since the last three decades, when the computer age started, as the software developments became more complex, so does the task of understanding them. Even some time, it is very difficult for the developers to interpret the source and object codes to the users. Objective: Based on the problems mentioned above, this work is developed software visualization for porous media with Graphical User Interface (GUI) application. Software visualization (SV) uses computer graphics to communicate the structure and behavior of computer software and algorithms. Fluid, which comprise both liquid and gases play very vital roles in human life and machines performances. This fluid always becomes useful when it tranfers or move from one point to another and this normally possible through pipe. The quantity or mass of fluid that passes through the pipe need to be determined especialy by the designers of pipe and the end users of the fluid. Method: Inorder to develop the software visualization for this work, the model which based on modified Heagen equation was modified to determine different mass flow rate at different temperature. The visual pipe for representation of different mass flow rate was developed with Autodesk Mayer and embedded in C# program for easy visualization. Results: With this software visualization, easy visualization of mass flow partterns can be examined and viewed. Conclution: This work will definitely assist the experts in fluid, pipes designers, and end users of fluid to determine at ease and at safe cost series of mass flow rate at different temperature.
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