DETERMINATION OF LOCAL HEAT TRANSFER COEFFICIENTS AT THE PISTON OF A HIGH SPEED DIESEL ENGINE BY EVALUATION OF MEASURED TEMPERATURE DISTRIBUTION

1979 ◽  
Author(s):  
Gerhard Woschni ◽  
Johann Fieger
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
High Speed ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Measured Temperature ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
High Speed Diesel

Local Heat Transfer Coefficients Measurement Under Micro Jet Impinging Using Nitrogen Gas (N2)

2016 ◽  
Author(s):  
Jeong-Heon Shin ◽  
Tomer Rozenfeld ◽  
Ashwin Vutha ◽  
Yingying Wang ◽  
Gennady Ziskind ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Heat Fluxes ◽  
Fluid Temperature ◽  
Transfer Coefficients ◽  
Nitrogen Gas ◽  
Heat Transfer Coefficients ◽  
Temperature Detector

Experimental and simulation studies were performed to reveal local heat transfer coefficients under jet impinging in micro domain with Nitrogen gas. The experimental device was made of a 500 μm thick Pyrex and 400 μm thick silicon wafers. On the Pyrex wafer, four 100 nm thick resistance temperature detector (RTD) thermistors and a heater were fabricated from titanium. Jet orifices were etched by deep reactive ion etching (DRIE) on a silicon wafer, which was attached to the Pyrex wafer through a vinyl sticker (250 μm thick). A 1.9 mm × 14.8 mm × 250 μm micro channel was formed by laser drilling into the sticker. Varying flow rates of Nitrogen gas and heat fluxes of the heater, temperatures of the four thermistors were collected and local heat transfer coefficients were inferred enabling to divulge the jet impinging cooling characteristics. Initial simulations were used to complement experiments and to obtain detailed flow patterns of the jet, temperature distribution on the heater area, and fluid temperature distribution.

scholarly journals Thermal analysis of the car windscreen

2019 ◽  
Vol 213 ◽  
pp. 02027
Author(s):  
Sylwia Ho ejowska ◽  
Tadeusz Orzechowski ◽  
Anna Pawi ska
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Outer Side ◽  
Physical Parameters ◽  
Passenger Compartment ◽  
Transfer Coefficients ◽  
Safe Driving ◽  
Heat Transfer Coefficients

The task of the ventilation and heating/cooling system in cars is to maintain the thermal comfort conditions in the passenger compartment to ensure safe driving. Designing such systems requires knowledge of many physical parameters, which often have to be specified individually. Such factors include heat transfer coefficients. The paper presents the results concerning the determination of the local heat transfer coefficients at the interface between the car windscreen and the cooling air from the inner side of the passenger compartment. The temperature of the outer side of the vehicle windscreen was measured using infrared thermography. The 2D mathematical approach describing the steady state heat transfer on a car windscreen was proposed. The temperature distribution was determined by the Trefftz method, and the heat transfer coefficient at the air–vehicle windscreen interface was calculated using the third type boundary condition. Graphs were used to represent thermographic images of the vehicle windshield, its temperature distribution, and corresponding values of local heat transfer coefficients as a function the length of the windshield. Results are presented and discussed.

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