If the temperature of each chip may not exceed 80°C, what is the maximum allowable power perchip? What is the maximum allowable power if a turbulence promoter is used to trip theboundary layer at the leading edge? Would it be preferable to orient the array normal, instead ofparallel, to the airflow? An array of 10 silicon chips, each of length L = 10 mm on a side, is insulated onone surface and cooled on the opposite surface by atmospheric air in parallel flow with T=20°Cand u = 30 m/s. When in use, the same electrical power is dissipated in each chip, maintaining auniform heat flux over the entire cooled surface.10 mm

Given, Temperature of Atmospheric Air, T∞=20°C Speed of air, u∞=30m/s Temperature of chip, Tc=80°C…

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=20°C and u = 30 m/s. When in use, the same electrical power is dissipated in each chip, maintaining a uniform heat flux over the entire cooled surface.

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=20°C and u = 30 m/s. When in use, the same electrical power is dissipated in each chip, maintaining a uniform heat flux over the entire cooled surface.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Water at 50°C flows through an automobile radiator tube 0.5 cm inner diameter, 50 cm long with a mean velocity of 1 m/s. The surface of the radiator tube is at 30°C. Determine the heat transfer coefficient using Colburn Analogy. [Use friction factor f=0.316 Re/5 for turbulent and f=0.184 Re4 for laminar.] The property values of Water at 50°C and 40°C are 50°C 40°C Density (kg/m³) 990 995 Cp (kJ/kg K) 4.182 4.179 k (W/m K) 0.640 0.628 V (m/s) 5.67 x 10"| 6.57 × 10" Pr 3.68 4.34
Consider two cases involving parallel flow of dry air at V = 1.5 m/s, T=45°C, and atmospheric pressure over an isothermal plate at T = 20°C. In the first case, Rex, = 5 x 105, while in the second case the flow is tripped to a turbulent state at x = 0 m. At what x -location, in m, are the thermal boundary layer thicknesses of the two cases equal? What are the local heat fluxes, in W/m², at this location for the two cases? x = 9jam 9 turb II = i i m W/m² W/m²
In the last step of a food supplement production, the food supplement is heated from 25C to 75C while passing through a 12.7 mm diameter thin-walled tube at a speed of 0.2 m / s. Proper heating is provided by an electric resistance heating system wrapped on the outer surface of the pipe. What is the heat flux in a pipe with a length of 10 m? The density of the fluid is given as 1000 kg / cubic meter , heat capacity 4000 J / kg-K, density 2x10^-3 kg / m-s, heat transfer coefficient 0.8 W / m-K and Prandtl number 10.
Calculate the convective heat transfer rate via the top and the two side walls of a refrigerated box trailer as shown in the figure. The trailer is cruising at a rate of 70 mph (31.3 m/s). The box trailer dimensions are 16 m long, 4.1 m high, and 2.6 m wide. Assume that the surface of the trailer is at uniform temperature of 10°C. The air temperature is 30°C. Because of the presence of the prime-mover in the front, the air flow can be assumed to be turbulent when it encounters the trailer. 187.4 kW Walls. Prime-mover 16 m 2.6 m
For safety reasons, parts can be directly blown by air. with dimensions of 15 cmx20 cm, which are not allowed to contact printed circuit board, 20 cm long 0.2 opened inside Cold air from a rectangular hole of cmx14 cm will be cooled. from electronic parts The heat generated is transmitted from the thin layer of the card to the duct, where it is combined with the air entering the duct at a temperature of 15 °C. is removed. The heat flux on the upper surface of the channel can be considered uniform and The heat transfer from the surfaces can be neglected. If the velocity of the air in the duct does not exceed (590) m/min and the surface temperature of the duct is constant at 50 °C, this circuit board can be safely placed on it. Calculate the maximum total power of the electronic parts to be placed.
Water at 340 K and a flow rate of 5 kg/s enters a black, thin-walled tube, which passes through a large furnace whose walls and air are at a temperature of 700 K. The diameter and length of the tube are 0.25 m and 8 m, respectively. Convection coefficients associated with water flow through the tube and airflow over the tube are 300 W/m²-K and 50 W/m².K, respectively. Water Tme= i m = 5 kg/s Tai K Tube, D = 0.25 m L = 8 m, ε = 1 Air T= 700 K -Furnace, Tur 700 K Write an expression for the linearized radiation coefficient corresponding to radiation exchange between the outer surface of the pipe and the furnace walls. Determine how to calculate this coefficient if the surface temperature of the tube is represented by the arithmetic mean of its inlet and outlet values. Use these expressions to determine the outlet temperature of the water, Tm,o, in K. Tmo
Air is to be heated by passing it across the tubes of an in-line tube bundle consisting of 8 rows of 25 mm OD tubes in the direction of flow and 10 tubes in each row normal to the flow. Air approaches the tube bank in the normal direction at 30 °C and 1 atm with a mean velocity of 10 m/s. The tube spacing is 37.5 mm in both parallel and normal to the flow. Calculate the heat transfer from the bundle per m of length when the tube surface temperature is 90 °C.
question is image only part a
A vehicle carrying refrigeration box is moving with a speed of 24 m/s on a road withambient temperature of 323 K. The dimensions of box are 3 m(H) × 4 m (W) × 10 m (L).Assume a wall temperature of 283 K and air flow is parallel to the longest side of the box.Neglecting the heat loss from the front side and backside of the box, calculate heat lossfrom four surfaces. For flow over flat surfaces useNu = 0.036(Re)0.8(Pr)1/3The properties of air at bulk mean temperature are : = 1.165 kg/m3, Pr = 0.701, cp = 1005 J/kg – K,  = 16 × 10–6m2/s
A horizontal thin plate with a length of L= 10 cm is tiled with a constant heat flux from the bottom and is cooled by air at the top. The air velocity is U = 40 m / s and the temperature is 20 ° C. What should be the minimum heat flux so that the plate temperature does not exceed 80°C? (kW / m²) v 17.94 x 10-6 m²/s = 0.0277 W/(m.K) Pr = 0.71
Air at 200C flowing at 25 m/s passes over a flat plate, the surface of which is maintained at 270°C. Calculate the rate at which heat is transferred from both the sides of the plate per unit width over a distance of 0.25 m from the leading edge. Properties of air at 145°C are Prandtl number = 0.687; Viscosity = 2.8 X 10-5 m2/s and thermal conductivity = 3.49 X 10-5 kW/m.K
Provide schematic diagram and solutions.