Heat Transfer

Fundamentals of Heat and Mass Transfer – Problem 1.30

ByAnthony January 2, 2022October 12, 2022

A spherical interplanetary probe of 0.5-m diameter contains electronics that dissipate 150 W. If the probe surface has an emissivity of 0.8 and it does not receive radiation from other surfaces, such as the sun, what is its surface temperature of the probe?

All sample problems and notes are based on the following textbook: Fundamentals of Heat and Mass Transfer Seventh Edition

ISBN-13: 9780470501979

ISBN-10: 0470501979

Edition: 7

Author: Theodore L. Bergman, Adrienne S. Lavine, Frank P. Incropera, David P. DeWitt

Publication date: 2011

Publisher: Wiley

Format: Hardcover 1072 pages

9780470501979-0470501979-Fundamentals of Heat and Mass Transfer

Heat Transfer

Experimental results for heat transfer over a flat plate with an extremely rough surface were found to be correlated by an expression of the form Nux=0.04 Rex0.9 Pr1/3 where Nux is the local value of the Nusselt number at a position x measured from the leading edge of the plate. Obtain an expression for the ratio of the average heat transfer coefficient hˉx to the local coefficient hx
ByAnthony January 2, 2022

Experimental results for heat transfer over a flat plate with an extremely rough surface were found to be correlated by an expression of the form Nux=0.04 Rex0.9 Pr1/3 where Nux is the local value of the Nusselt number at a position x measured from the leading edge of the plate. Obtain an expression for the ratio of…

Read More Experimental results for heat transfer over a flat plate with an extremely rough surface were found to be correlated by an expression of the form Nux=0.04 Rex0.9 Pr1/3 where Nux is the local value of the Nusselt number at a position x measured from the leading edge of the plate. Obtain an expression for the ratio of the average heat transfer coefficient hˉx to the local coefficient hx
Heat Transfer

Fundamentals of Heat and Mass Transfer Seventh Edition Problem – 1.23
ByAnthony December 30, 2021October 12, 2022

A transmission case measures W = 0.30 m on a side and receives a power input of Pi= 150 hp from the engine. If the transmission efficiency is η=0.93 and air flow over the case corresponds T =30 degree C and h=200 W/m2-K. What is the surface temperature of the transmission? All sample problems and notes…

Read More Fundamentals of Heat and Mass Transfer Seventh Edition Problem – 1.23
Heat Transfer

Fundamentals of Heat and Mass Transfer – Problem 1.9
ByAnthony January 2, 2022October 12, 2022

A glass window of width W= 1 m and height H = 2 m is 5 mm thick and has a thermal conductivity of kg 1.4 W/m·K. If the inner and outer surface temperatures of the glass are 15°C and -20°C, respectively, on a cold winter day, what is the rate of heat loss through…

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Heat Transfer

Fundamentals of Heat and Mass Transfer – Problem 2.31
ByAnthony January 4, 2022October 12, 2022

The temperature distribution across a wall 0.3 m thick at a certain instant of time is T(x) = a + bx + cx2, where T is in degrees Celsius and x is in meters, a = 200 °C, b = -200 °C /m, and c = 30 °C /m2, The wall has a thermal conductivity…

Read More Fundamentals of Heat and Mass Transfer – Problem 2.31
Heat Transfer

Fundamentals of Heat and Mass Transfer – Problem 2.5
ByAnthony January 2, 2022October 12, 2022

Assume steady-state, one-dimensional heat conduction through the symmetric shape shown. Assuming that there is no internal heat generation, derive an expression for the thermal conductivity k(x) for these conditions: A(x) = (1 – x), T(x) = 300(1 – 2x – x3), and q = 6000 W, where A is in square meters, T in kelvins,…

Read More Fundamentals of Heat and Mass Transfer – Problem 2.5
Heat Transfer

temperature of each chip may not exceed 80°C, what is the maximum allowable power per chip? What is the maximum allowable power if a turbulence promoter is used to trip the boundary layer at the leading edge?
ByAnthony January 2, 2022October 12, 2022

An array of 10 silicon chips, each of length L=10 mm on a side, is insulated on one surface and cooled on the opposite surface by atmospheric air in parallel flow with T∞=24°C and u∞=40m/s. When in use, the same electrical power is dissipated in each chip, maintaining a uniform heat flux over the entire cooled surface….

Read More temperature of each chip may not exceed 80°C, what is the maximum allowable power per chip? What is the maximum allowable power if a turbulence promoter is used to trip the boundary layer at the leading edge?