Consider using the experimental methodology of Problem4.70 to determine the convection coefficient distributionabout an airfoil of complex shape.
Accounting for conduction in the metal sheathing andradiation losses to the large surroundings, determine theconvection heat transfer coefficients at the locationsshown. The surface locations at which the temperaturesare measured are spaced 2 mm apart. The thickness ofthe metal sheathing is
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Introduction to Heat Transfer
- 3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the atmosphere from outer space. If its original temperature is 38°C, the effective average temperature of the atmosphere is 1093°C, and the effective heat transfer coefficient is , estimate the temperature of the shell after reentry, assuming the time of reentry is 10 min and the interior of the shell is evacuated.arrow_forwardThe heat transfer coefficient for a gas flowing over a thin float plate 3-m long and 0.3-m wide varies with distance from the leading edge according to hc(x)=10x1/4Wm2K If the plate temperature is 170C and the gas temperature is 30C, calculate (a) the average heat transfer coefficient, (b) the rate of heat transfer between the plate and the gas, and (c) the local heat flux 2 m from the leading edge. Problem 1.18arrow_forwardExample 1.4 length. It is lined inside with 3 cm of insulating material of k = 0.042 W/mK. It is flying at a height where the average outside temperature is - 30°C. To find: The rate of heating required to maintain the compartment at 20°C for passenger comfort. Given: A jet aircraft compartment is assumed to be a cylindrical tube of 3-m diameter and 20-marrow_forward
- 2.2: Water at a temperature of T∞= 25°C flows over one ofthe surfaces of a steel wall (AISI 1010) whose temperatureis Ts,1= 40°C and thermal conductivity of steel is 671 w/m.k. The wall is 0.35 m thick, and itsother surface temperature is Ts,2= 100°C. For steadystateconditions what is the convection coefficient associatedwith the water flow?arrow_forwardAn underwater sonar that maps the ocean bathymetry is encapsulated in a sphere with a diameter of 85 mm. During operation, the sonar generates heat at a rate of 300W. What is the sonar surface temperature when it’s located in a water column where the temperature is 15o C and the water current is 1 m/sec? The sonar was pulled out of the water without turning it off, thus, it was still working. The air temperature was 15o C and the air speed was 3 m/sec. What was the sonar surface temperature? Was there any reason for concern?arrow_forwardHeat transferarrow_forward
- = A long rod of 60-mm diameter and thermophysical properties p 8000 kg/m³, c C = 500 J/kg-K, and k = 50 W/m-K is initially at a uniform temperature and is heated in a forced convection furnace maintained at 750 K. The convection coefficient is estimated to be 1000 W/m².K. What is the centerline temperature of the rod when the surface temperature is 570 K? The centerline temperature of the rod is i K.arrow_forward1. A closed container filled with hot coffee as shown below is in a room whose air and walls are at fixed temperature much lower than the coffee. Identify all heat transfer process that contributes to cooling of the coffee. Draw schematics, make necessary assumptions (black body, thickness, materials and convection coefficient) and find the heat flux and temperature of all points of heat transfer if the temperature of coffee and outside surrounding is at 95°C and 28°C respectively. Hot coffee Cover Air space Plastic flaskarrow_forwardThermal treatment of a steel cube, of 10 cm side length, L, requires a two step cooling process. In the first step, the cube at the uniform temperature of 500°C is placed in air where it is cooled to 250°C. In the second step, it is moved to large oil bath of temperature 20°C where the heat transfer coefficient at all surfaces is the same and equal to h = 50 W m-2 K-1. %3D Calculate the total amount of energy lost by the cube and show that the lumped capacitance method can be used to calculate the temperature during the second step of cooling. Calculate the time necessary to reduce the cube temperature to 50°C. Thermal properties Density = 8000 kg m-3 Cp= 480 J kg-1 K-1 k = 30 W m-1 K-1. %3Darrow_forward
- Earrow_forwardIn infinitely long parallel plates, Biot number and Fourier number are 0.2 and (10).Find the temperature distribution at center, temperature distribution at plate surface, andactual to maximum heat transfer ratio. uses charts/table also if neededarrow_forwardRead the question carefully and give me right solution according to the question. A solid copper sphere (k = 393 W/mK), 10 mm in diameter, initially at 800C is placed in an air stream at 300 C. The temperature is dropped to 650C after 61 seconds. Calculate the value of convection coefficient. Assume properties as ρ= 8925 kg/m3, C = 397 J/kg K.arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning