3. (40pts) A furnace is shaped like a long equilateral triangular duct where the width of...
Consider a circular furnace that is 0.5 m long and 0.5 m in diameter. The two ends have diffuse, gray surfaces that are maintained at 400 and 500 K with emissivities of 0.4 and 0.5, respectively. The lateral surface is also diffuse and gray with an emissivity of 0.7 and a temperature of 800 K. Determine the net radiative heat transfer rate from each of the surfaces.
A furnace has the form of a truncated conical section, perfectly insulated with an emissivity of 0.3. Assume that all the surfaces are diffuse-gray. s shown in the schematic. The floor of the furnace hasa emissivity of e 0.7 and is maintained at 1000 K with a heat flux of 2200 W/m2, The lateral wall is D 20 mm A L 50 mm A D, 40 mm (a) Determine the temperature of the upper surface, T, if its emissivity is...
Problem III - Solve on Booklet 3 (33 pts) Consider two parallel, aligned disks, 0.4 m in diameter and separated by 0.1 m. The first disk (A1), with an emissivity of 0.6, is maintained at a uniform temperature of 500 K. The second disk (A2), with an emissivity of 0.8, has a well-insulated back side while its front side faces the first disk. The two parallel disks are located in a large room (A3) whose walls are maintained at 300...
*Problem 13.056 An electric furnace consisting of two heater sections, top and bottom, is used to heat treat a coating that is applied to both surfaces of a thin metal plate inserted midway between the heaters. Heater - Plate Sidewalls L L L LLLLLLLLL ||||||||| Heater The heaters and the plate are 2 m x 2 m on a side, and each heater is separated from the plate by a distance of L = 0.5 m. Each heater is well...
Consider a long duct constructed with diffuse and gray walls. The width of each wall is 1 m. Heat transfer is from surface 1 to surface 2, while surface 3 is completely insulated and cannot absorb heat (which means 93 = 0). Az, T2 = 700 K, Ez = 0.5 A4, T1 = 1000 K, £z = 0.33- -A3, T3 , £z = 0.8 a. Provide a sketch and state your assumptions b. Determine the net radiation transfer from surface...
Homework 7 heat transfer 2018-20 1) A horizontal tube of 12.5-mm dimeter with an outer srface temperature of 240°C is placed in a room with an air temperature of 20°C. Estimate the heat transfer rate per unit length of the tube due to free convection. 2) Air at -10°C flows at 10 m/s over the roof plate of two 5m length rooms whose air is at Too-200C. The roof plate is 0.20-m thick concrete (k = 0.6 w/ m. K)....
Problem 3 (20 points) A cross-flow heat exchanger consists of a bundle of 32 tubes in a long duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters of 10.2mm and 12.5mm and has to be cooled to 136°C. The tubes are made of steel of thermal conductivity k-40 W/m.K. Air at 10°c enters the exchanger (unfinned) with a volumetric flow rate of 1.0 m3/s. The convective heat transfer coefficient...
Two large parallel plates with surface conditions approximating those of a blackbody are maintained at 800°C and 100°C, respectively. Determine the rate of heal transfer by radiation between the plates in Wim and the radiative heat transfer coefficient in W/m K ) 12 Write down the one-dimensional sent heal conduction equation for a plane wall with constant thermal conductivity and heat generation in its simplest form, and indicate what each variable represents 13 Write down the one-dimensional transient heat conduction...
just now i sent this questions. this is the answer given. however the answer i afraid that he used formula that is not for constant surface temperature and noncircular formula. this is the formula foe the noncircular tube. because the question ask about triangle. my problem is, i cannot answer question 1(b) that ask the heat transfer coefficient, h. please help me. thank you. this pic is a note on constant surface temperature. page 482 ref: HEAT AND MASS TRANSFER:...
summatize the following info and break them into differeng key points. write them in yojr own words apartus 6.1 Introduction—The design of a successful hot box appa- ratus is influenced by many factors. Before beginning the design of an apparatus meeting this standard, the designer shall review the discussion on the limitations and accuracy, Section 13, discussions of the energy flows in a hot box, Annex A2, the metering box wall loss flow, Annex A3, and flanking loss, Annex...