3. Consider a hot automotive engine, which can be approximated as a 0.6 m high, 0.3 m wide, and 0.9 m long rectangular block. The bottom surface of the block is at a temperature of 90°C and has an emissivity of 0.9. The ambient air is at 23°C, and the road surface is at 28°C. The fluid properties of air are determined at the film temperature and can be found in the tables at the end of the tutorial. a. Determine the rate of heat transfer from the bottom surface of the engine block by convection and radiation as the car travels at a velocity of 60 km/h.

3. Consider a hot automotive engine, which can be approximated as a 0.6 m high, 0.3 m wide, and 0.9 m long rectangular block. The bottom surface of the block is at a temperature of 90°C and has an emissivity of 0.9. The ambient air is at 23°C, and the road surface is at 28°C. The fluid properties of air are determined at the film temperature and can be found in the tables at the end of the tutorial. a. Determine the rate of heat transfer from the bottom surface of the engine block by convection and radiation as the car travels at a velocity of 60 km/h.

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

A 0.10-mm-diameter glass tube is inserted into water at 100°C in a tub to observe capillary rise phenomenon. Determine the capillary rise of water in the tube. (a) What would happen if the water is cooled down to 20°C? (b) What would happen if 0.10mm tube replaced with 0.3mm tube?
Explain why convection happens more often in gases and liquids than solids.
Write the comparison between forced and free convection in a non-isothermal system?
Air is flowing at 35°F with a velocity of 12 ft/s over a plate 10 ft long and 2 ft wide. The plate is at room temperature. Determine the coefficients of local friction, heat transfer coefficient and heat transfer rate of the plate at 1 ft intervals along the length. Plot on the same graph the results as a function of distance from the leading edge, the graph will be reviewed. The table of thermal properties of air is on the platform. Report in the following boxes your results for a length of 5 ft.
You have an object with a characteristic length of 1.8 cm. For the following conditions, determine the Rayleigh Number (evaluate the fluid properties at the film temperature): a) Water at a free-stream temperature of 50°C; object at a temperature of 14°C. b) Unused Engine Oil, at a temperature of 13°C; object at a temperature of 61°C. c) Air at atmospheric pressure, and a temperature of 11°C; object at a temperature of 43°C.
Heat transfer
In the arctic sea, the ice sheets are melting. Let's calculate the temperautre distribution in one such ice sheet. The sheet is 2 m thick. Under the sheet there is ice-water mixture and it can be assumed that the temperature of the bottom surface of the ice sheet is approximately 0°C. Air at -20°C is blowing above the sheet. The convection coefficient of air is 15 W/m².K. The thermal conductivity of ice is 2.2 W/m.K. What is the temperautre of icesheet at its center (i.e., at 1 m from the surface)?
Thick fluids such as asphalt and waxes and the pipes in which they flow are often heated in order to reduce the viscosity of the fluids and thus to reduce the pumping costs. Consider the flow of such a fluid through a 100-m-long pipe of outer diameter 30 cm in calm ambient air at 0oC. The pipe is heated electrically, and a thermostat keeps the outer surface temperature of the pipe constant at 250C. The emissivity of the outer surface of the pipe is 0.8, and the effective sky temperature is-300C. Determine the power rating of the electric resistance heater, in kW, that needs to be used. Also, determine the cost of electricity associated with heating the pipe during a 10-h period under the above conditions if the price of electricity is $0.09/kWh. Properties The properties of air at 1 atm and the film temperature of (Ts+To)/2 = (25+0)/2 = 12.5°C are: k = 0.02458 W/m.oC, v = 1.448x10-5 m2/s, Pr = 0.7330 D=m
Solve it correctly please. I will rate accordingly with 4votes but I need correct answer.
2. Consider laminar fully-developed flow through two smooth isothermal tubes. One tube has circular cross-section the other has square cross-section. The cross-sectional area is the same for both tubes. Show that the convection coefficient in these two flows are related as hcircular 1.088hsquare- %3D Assume that the fluid properties are the same.
Thank you for answering this question. Please you specify each step as soon as possible. Good Luck! Thank you. If you want to cool a thin plate by natural convection quickly, will you hold it as shown in position (a) with the long dimension parallel to the direction of gravity or in position (b) with the shorter dimension parallel to the direction of gravity and why? Assume Laminar flow. (b)
Water at 25 °C is flowing at a velocity of 0.45 m/s in a tube having a mass transferarea (Black region in the figure) of 4.42.10-5 m2. The tube is 1.2 m long with the walls coatedwith formic acid. The solubility of formic acid in water is 100000 mg/L. Viscosity of water is8.71 x 10-4 Pa.s and the density of water is 996 kg/m3. Assuming that the velocity profile is fullydeveloped.a. Determine the flow type.b. Calculate the convective mass-transfer coefficient k'c.c. Calculate the flux of NA.