4-The air inside an electronics package housing has a temperature of50°C. A "chip" in this housing has internal thermal power generation(heating) rate of 3 X 10³ W. This chip is subjected to an air flowresulting in a convective coefficient h of 9 W/m2.C over its two mainsurfaces which are 0.5 cm X 1.0 cm. Determine the chip surfacetemperature neglecting radiation and heat transfer from the edges.Ans(T, 53.33C).

Answered: Image /qna-images/answer/bdf8ea41-7316-4eae-8988-7478293e8030.jpg

Answered: 4-The air inside an electronics package…

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.27P

See similar textbooks

Similar questions

1.21 In an experimental set up in a laboratory, a long cylinder with a 5-cm diameter, and an electrical resistance heater inside its entire length is cooled with water flowing crosswise over the cylinder at and a velocity of 0.8 m/s. For these flow conditions, 20 kW/m of power is required to maintain a uniform temperature of at the surface of the cylinder. When water is not available, air at is used with a velocity of 10 m/s to maintain the same surface temperature. However, in this case, the cylinder surface heat dissipation rate is reduced to 400 W/m. Calculate the convection heat transfer coefficients for both water and air, and comment on the reason for the differences in the values.
1.67 In beauty salons and in homes, a ubiquitous device is the hairdryer. The front end of a typical hairdryer is idealized as a thin-walled cylindrical duct with a 6-cm diameter with a fan at the inlet that blows air over an electric heating coil as schematically shown in the figure. The design of this appliance requires two power settings, with which the air blown over the electric heating coil is heated from the ambient temperature of to an outlet temperature of and with exit air velocities of 1.0 m/s and 1.5 m/s. Estimate the electric power required for the heating coil to meet these conditions, assuming that heat loss from the outside of the dryer duct is neglected.
Determine the rate of heat loss from the wall of a building resulting from a 16 km/h wind blowing parallel to its surface. The wall is 24 m long and 6 m high, its surface temperature is 27C, and the temperature of the ambient air is 4C.
An electrical transmission line of 1.2-cm diameter carries a current of 200 amps and has a resistance of 310-4 ohm per meter of length. If the air around this line is at v, determine the surface temperature on a windy day, assuming a wind blows across the line at 33 km/h.
Water is entering a heated tube at mass ow rate of 1.2 kg/s. The temperature at the inlet is 20 C and at the outlet is 80 C. Assume the surface temperature of the tube is 100 C. The convection coe cient of the water ow is 28 W=m2 C. The speci c heat and density of water can be assumed to be 4180 J=kg C and 990 kg=m3. What is the rate of heat transfer to water during this proces
A steam is flowing through a 5.7 m long of steel tube that has inner and outer radii of r, = 0.015 and r, 0,024 m, and a thermal conductivity of 0.14 W/m.K. The steam and the outer surface of the tube is maintained at constant temperature of 150 °C and the air = 25 °C, h = 0.35 W/m2.k) is surrounding the tube. To prevent the outer surface of the steel from the environmental conditions, a material that has a thermal conductivity of 0.014 W/m.k is wrapped over the outer surface of the steel. What is the maximum heat transfer from the steam to the air (W)? NOTE: Enter your answer. Answer Air Th Steam Steel Tr 111 To
Heat Transfer (Third year) 2020- 2021 Homework 01-03-2021 By Dr. Basil Noori Merzah one-dimensional heat transfer and disregarding radiation, determine the rate of heat transfer through the wall. Q4/ Steam at T01-320°C flows in a cast iron pipe (k=80W/m. C) whose inner and outer diameters are D,=5cm, and D,-5.5cm, respectively. The pipe is covered with 3 cm thick glass wool insulation with k=0.05W/m. C. Heat is lost to the surroundings at T2-5°C by natural convection and radiation, with a combined heat transfer coefficient to be h,=18W/m."C. Taking the heat transfer coefficient inside the pipe to be 2 0 h,-60W/m. C, determine the rate of heat loss from the steam per unit length of the pipe. Also determine the temperature drops across the pipe shell and the insulation. Q5/ Determine the overall heat transfer coefficient U based on the outer surface of a D=2.5cm, and D =3.34 cm steel pipe (k=54.0W/m. C) for the following conditions: inside and outside heat transfer coefficients are…
Heat transfer Calculate the heat transfer rate in Btu/hr through the pipe ona stainless steel pipe with a length of 12m has an inner diameterof 10in and an outer diameter of 13in. The temperature of theinner surface of the pipe is 50°C and the temperature of theouter surface is 48°C. The thermal conductivity of the stainlesssteel is 187 W/m-°C. Show complete solution in a clear paper.
A:Find the amount of heat transferred through an iron fin of thickness 5 mm, length 10 cm and width 100 cm. Also determine the temperature difference e at the tip of the fin at: 1- adiabatic tip, 2-heat convection at the tip. Assuming the atmospheric temperature of 28°C K=50 w/mK, h=10 w/m’K, O,=80°C. B-Why is the dimensional heat flow assumption important in the analysis of fins problems? C- Why are the annular fins more efficiency than others?.
Convection 2. For a boiling process such as shown in Figure below, the ambient temperature Tin Newton's law of cooling is replaced by the saturation temperature of the fluid Tsat. Consider a situation where the heat flux from the hot plate is q=20 x 105 W/m². If the fluid is water at atmospheric pressure and the convection heat transfer coefficient is hw=20 x 103 W/m2 K, determine the upper surface temperature of the plate, Ts, w. In an effort to minimize the surface temperature, a technician proposes replacing the water with a dielectric fluid whose saturation temperature is Teat, d=52 °C. If the heat transfer coefficient associated with the dielectric fluid is h = 3 x 103 W/m2 K, will the technician's plan work?
Consider a steam pipe of length 20 m, inner radius 7 cm, ouler radius n 12 cm, and thermal conductivity 20 Wim K. The inner and outer surfaces of the pipe are maintained at average temperatures of T 160'C and Ta 65'C, respectively. Applying a general relation for the temperahure distribution inside the pipe under steady conditions, determine the rate of heat loss from the stoam through the pipe.
Need answer ASAP! Thank you Water at 5°C is being used to cool apples from an initial temperature of 25° to 10°C. Thewater flow over the surface of the apple creates a convective heat-transfer coefficientof 10 W/(m2-K). Assume the apple can be described as a sphere with an 8 cm diameterand the geometric center is to be reduced to 10°C. The apple properties include thermalconductivity of 0.4 W/(m-K), specific heat of 3.950 kJ/(kg-K), and density of 940 kg/m3 a. Determine the time that the apples must be exposed to the water.b. If the apple is submerged only for 2 hours, what will be its center temperature?

SEE MORE QUESTIONS

Recommended textbooks for you

Principles of Heat Transfer (Activate Learning wi…

Mechanical Engineering

ISBN:

9781305387102

Author:

Kreith, Frank; Manglik, Raj M.

Publisher:

Cengage Learning