Pumping Power Performance and Frictional Resistance of Textured Microchannels in Gaseous Slip Flows

2021 ◽  
Vol 60 (5) ◽  
pp. 2290-2299
Author(s):  
Richie Garg ◽  
Soham Mujumdar ◽  
Amit Agrawal
Keyword(s):  
Frictional Resistance ◽  
Pumping Power ◽  
Power Performance ◽  
Slip Flows

Heat Transfer versus Pumping Power Performance for Cross-Inclined Tube Banks

1973 ◽  
Vol 15 (5) ◽  
pp. 382-386 ◽  
Author(s):  
E. M. Smith
Keyword(s):  
Heat Transfer ◽  
Pumping Power ◽  
Power Performance ◽  
Flow Rates ◽  
Inclined Tube ◽  
Tube Banks

Thermal performances of several cross-inclined in-line tube banks in crossflow are compared with parallel in-line and parallel staggered tube banks of similar geometry, and found to be superior at higher flow rates.

Augmented Heat Transfer in a Recovery Passage Downstream From a Grooved Section: An Example of Uncoupled Heat/Momentum Transport

1995 ◽  
Vol 117 (2) ◽  
pp. 303-308 ◽  
Author(s):  
M. Greiner ◽  
R.-F. Chen ◽  
R. A. Wirtz
Keyword(s):  
Heat Transfer ◽  
Reynolds Numbers ◽  
Pumping Power ◽  
Power Performance ◽  
Velocity Measurements ◽  
Cross Sectional ◽  
Number Range ◽  
Transverse Grooves ◽  
Pressure And Velocity Measurements ◽  
The Heat Transfer Coefficient

Earlier experiments have shown that cutting transverse grooves into one surface of a rectangular cross-sectional passage stimulates flow instabilities that greatly enhance heat transfer/pumping power performance of air flows in the Reynolds number range 1000 < Re < 5000. In the current work, heat transfer, pressure, and velocity measurements in a flat passage downstream from a grooved region are used to study how the flow recovers once it is disturbed. The time-averaged and unsteady velocity profiles, as well as the heat transfer coefficient, are dramatically affected for up to 20 hydraulic diameters past the end of the grooved section. The recovery lengths for shear stress and pressure gradient are significantly shorter and decrease rapidly for Reynolds numbers greater than Re = 3000. As a result, a 5.4-hydraulic-diameter-long recovery region requires 44 percent less pumping power for a given heat transfer level than if grooving continued.

Modeling and Preliminary Experiment for Rarefied Gas Flows in Constricted Microchannels

2008 ◽  
Author(s):  
Xiaohui Guo ◽  
Chihyung Huang ◽  
Alina Alexeenko ◽  
John P. Sullivan
Keyword(s):  
Rarefied Gas ◽  
Numerical Models ◽  
Pressure Ratio ◽  
Frictional Resistance ◽  
Manufacturing Defects ◽  
Slip Regime ◽  
Rarefied Gas Flows ◽  
Mass Flowrate ◽  
Accommodation Coefficients ◽  
Slip Flows

Gaseous slip flows in 3D rectangular microchannels with constrictions have been study numerically, and the experiment using pressure-sensitive-paints (PSP) for polymer microchannel pressure measurements are proposed. Constrictions inside microchannels, either being manufacturing defects or functional design features such as micro-orifices or micro-nozzles, will change the flow pattern because of additional frictional resistance and flow separation. In current research, mass-flowrate reduction due to constrictions has been investigated numerically for air flows in the slip regime, where Knudsen number ranges from 0.003 to 0.07. The results have been compared with both straight microchannels and with 3D analytical solutions. Similar to nozzle cases at macroscale, chocked flows has been observed at the critical pressure ratio of about 1.89. A numerical model including finite inlet and outlet chambers has been used in simulations to evaluate effects of reflection waves. Slip effects have been studied for different accommodation coefficients in presence of constrictions. By implementing multi-species numerical models, thermal induced mass transport has also been studied. Preliminary experiment based on PSP measurement for polymer microchannels has able to generate high spatial resolution pressure data, which are comparable with numerical simulations. Finally, further improvement of experimental setup is discussed.

Comparison of the Power Performance Characteristics of the 15 kW Converter-fed Inductor and Asynchronous Electric Drives

2017 ◽  
pp. 44-47
Author(s):  
Serguei Aleksandrovich PAKHOMIN ◽  
◽  
Dmitrii Viktorovich KRAINOV ◽  
Fedor Aleksandrovich REDNOV ◽  
Vladinir Leonidovich KOLOMEITSEV ◽  
...  
Keyword(s):  
Performance Characteristics ◽  
Power Performance ◽  
Electric Drives

Power Test System Development and Dynamic Performance State Estimation Based on Hub Motor Vehicle

2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao
Keyword(s):  
Real Time ◽  
Dynamic Performance ◽  
Test System ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Maximum Speed ◽  
Performance Parameters ◽  
Power Performance ◽  
Power Test ◽  
The Real

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.

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