An array of electronic chips is mounted within a sealed rectangular enclosure, and cooling isimplemented by attaching an aluminum heat sink
If cooling is implemented by water flow through the heat sink, with
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Fundamentals of Heat and Mass Transfer
- solve. heat transferarrow_forwardThe first part of the question has been worked on, where the heat transfer was calculated to be 6.770 kilowatt, but the problem also asks to calculate the temperature of the outer most surface. What is the temperature of the outer most surface?arrow_forwardHomework O H.W. 1: The walls of a refrigerator are typically constructed by sandwiching a layer of insulation between sheet metal panels. Consider a wall made from fiberglass insulation of thermal conductivity k; = 0.046 W/m.K and thickness L, = 50 mm and steel panels, each of thermal conductivity k, = 60 W/m.K and thickness L, = 3 mm. If the wall separates refrigerated air at T = 4 C from ambient air at T,. = 25 C, what is the heat gain per unit surface area? Coefficients associated with natural convection at the inner and outer surfaces may be approximated as h, = h, = 5 W/m?.K. %3D %3D L; = 0.050 m K K Lo = 0.003 m Refrigerated air Ambient air Too.i = 4°C hi = 5 W/m2-K To,o = 25°C ho = 5 W/m2-K %3D Panel (2) kp = 60 W/m-K Insulation k; = 0.046 W/m-K 22 Warith Alanbiyaa (Dr. ALI M) Heat Transfer Page 11 ofarrow_forward
- Below is a diagram of a pipe with 5 m radius, temperature of 5000 K, and k = 450 W/m-K. The pipe is covered by a steel that is 1.8 m thick with k = 17 W/m-K. The temperature inside is 5000 K while the temperature outside is 800 K. TB = 800 K TA = 5000 K k = 450 W/m-K K = 15 W/m-K Answer the following: 1. Calculate the system's heat loss per unit length (W/m²). 2. Calculate the temperature between the pipe and the steel (temperature in K). 5 m 1.8 m/arrow_forwardsolve 1 and 4arrow_forwardWhat is the length of a copper tube with the heat loss of 500 Watts? A hot liquid which is 40℃ flows inside of it which have surface conductance of 5W/(m^2℃) and the inside diameter of the copper tube is 10 mm and thickness of 3 mm with thermal conductivity of 25W/(m℃) . Outside fluid temperature is 20℃ with surface conductance of 3W/(m^2℃).arrow_forward
- Please include a fbd of the problemarrow_forward(3) A thick silver wire resistance heater measures 2 m in length with a diameter of 2.5 cm. The power output of the wire is 400 watts. If the maximum temperature in the wire is 800 K, what is the temperature of the wire at r = cm? 2 L=2m 0.75 • Q = Egen = 400 W wire d = 2.5cm = 0.025m R = 0.0125m Tmax=800k = T (r = 0) T(r = 0.0075m) = ? Rarrow_forwardAs2 Calculate the temperature 7 cm into the mineral wool layer from the warm side measured in one wall that is built from the outside in according to the following material layers: Wood panel ventilated R = 0.20 m2K / W Mineral wool 200 mm λ = 0.033 W / mK Plastic foil R ≈ 0 m2K / W Plasterboard 13 mm λ = 0.22 W / mK The temperature outside is -10 ◦C and inside 22 ◦C. The heat transfer resistors are on the inside Rsi = 0, 13 and on the outside Rse = 0, 04 m2K / Warrow_forward
- The inside wall of a furnace is at 2100oF and the outside wall is at 300oF. The wall of a furnace must be designed to transmit no more than 220 Btu/hr-ft2. Two types of bricks are available for construction:TYPE A: k = 0.38 Btu/ hr-ft-R with an allowable maximum temperature of 1400oFTYPE B: k = 0.98 Btu/ hr-ft-R with an allowable maximum temperature of 2300oF Both types of bricks have the same dimensions (9” x 4.5” x 3”) but the cost for Type B brick is twice the cost of Type A brick. Illustrate the order of arrangement of bricks A and B in the furnace wall (with thickness, estimated temperatures at the interface between walls A and B and at the interior and exterior surface, the transport area and direction of transfer included)arrow_forwardThe inside wall of a furnace is at 2100oF and the outside wall is at 300oF. The wall of a furnace must be designed to transmit no more than 220 Btu/hr-ft2. Two types of bricks are available for construction:TYPE A: k = 0.38 Btu/ hr-ft-R with an allowable maximum temperature of 1400oFTYPE B: k = 0.98 Btu/ hr-ft-R with an allowable maximum temperature of 2300oF Both types of bricks have the same dimensions (9” x 4.5” x 3”) but the cost for Type B brick is twice the cost of Type A brick. If a 15 ft2 wall is to be constructed, how many bricks will be used? how many brick A and how many brick B?arrow_forwardThe inside wall of a furnace is at 2100oF and the outside wall is at 300oF. The wall of a furnace must be designed to transmit no more than 220 Btu/hr-ft2. Two types of bricks are available for construction:TYPE A: k = 0.38 Btu/ hr-ft-R with an allowable maximum temperature of 1400oFTYPE B: k = 0.98 Btu/ hr-ft-R with an allowable maximum temperature of 2300oF Both types of bricks have the same dimensions (9” x 4.5” x 3”) but the cost for Type B brick is twice the cost of Type A brick. Model the wall as one-dimensional and determine the most economical arrangement of the bricks. Include:a drawing labeled with all given informationthe variables used in the appropriate places on the drawing (along with values and units, if provided)a thermal circuit showing the paths for heat transmissionequations and calculationsCalculations that show that the maximum temperature for Type A brick does not exceed 1400oFA recommendation for the number and orientation of the bricks. The inside temp is 2100f…arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning