Using the naphthalene sublimation technique. the radial distribution of the local convection
The stagnation point Sherwood number
Obtain an expression for the average Nusselt number
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Fundamentals of Heat and Mass Transfer
- Nitrogen enters a converging–diverging nozzle at 700 kPa and 400 K with a negligible velocity. Determine the critical velocity, pressure, temperature, and density in the nozzle.arrow_forwardIn which medium does a sound wave travel faster: in air at 20°C and 1 atm or in air at 20°C and 5 atm?arrow_forwardAir at 20°C, 1 atm flows with a velocity of 4.5 m/s over a flat plate having a sharp leading edge. The plate surface isisothermal at 60°C.(a)Find out the distance from leading edge at which the flow in the boundary layer changes from laminar to turbulent.(b)Using exact solution,determinethe following parameters at the location established at part (a):(i)Thickness of the hydrodynamic boundary layer(ii)Thickness of the thermalboundary layer(iii)Local convective heat transfer coefficient(iv)Average convective heat transfer coefficient(v)Heat transfer rate from both sides per unit width of the plate(vi)Mass entrainment in the boundary layer(vii)The skin friction coefficientarrow_forward
- Agas at 0°C and avelocity of 2.5 m/s, flows over a 1.2 m long, 2m wide plate that is maintained at 80°C. If the gas properties are: Density = 1.142 kg/m3 , cp = 1.04 kJ/kg.K, ν= 15.63×10 -6m2 /s, k = 0.0262 W/m.K,and Pr= 0.708,determine: (a)The critical length of the flow[m] (b)The average heat transfer coefficient[W/m2 .K] (c)Total rate of heat transfer from the plate[W]arrow_forwardCalculate the stagnation temperature and pressure for the following substances flowing through a duct: (a) helium at 0.25 MPa, 50°C, and 290 m/s; (b) nitrogen at 0.15 MPa, 50°C, and 300 m/s; and (c) steam at 0.1 MPa, 350°C, and 340 m/s.arrow_forwardFuel with heating value (HV) of 39,000 kJ/kg is burned by spraying in to 16-cm-diameter tabular combustionchamber. The air enters at 450 K, 380 kPa, and 55 m/s as shown in Figure Q3. If the exit Mach number is 0.8,determine (a) the exit temperature and,(b) the rate at which the fuel is burned.Properties of air: Specific heat capacity ratio k = 1.4, Specific heat at constant pressure c, = 1.005 kJ/kg.K,and Gas constant R = 0.287 kJ/kg.K.Use Appendix 2 for Rayleigh flow functions for an ideal gas with k = 1.4 Assume:1. Rayleigh flow (i.e., steady one-dimensional flow of an ideal gas with constant properties through aconstant cross-sectional area duct with negligible frictional effects) are valid. 2. combustion is compleso, and it is treated as a heat addition process, with no change in the chemical composition of flow 3.The increase in mass flow rate due to fuel in ection is disregardeo.arrow_forward
- The velocity and temperature of the flow ahead of a normal shock wave are 1215 m/s and 300 K, respectively. Calculate the velocity of the flow behind the shock.arrow_forwardWhat is the characteristic aspect of Rayleigh flow? What are the main assumptions associated with Rayleigh flow?arrow_forwardB) Does the Mach number of a gas flowing at a constant speed remain constant?arrow_forward
- During the entry of the space shuttle into the earth’s atmosphere, maximum stagnation point heating occurs at the trajectory point corresponding to an altitude of 68.9 km, where ρ∞ = 1.075 × 10−4 kg/m3, and a flight velocity of 6.61 km/s. At this point on its entry trajectory, the shuttle is at a 40.2 degree angle of attack, which presents an effective nose radius at the stagnation point of 1.29 m. If the wall temperature is Tw = 1110 K, calculatethe stagnation point heating rate.arrow_forwardAre the isentropic relations of ideal gases applicable for flows across (a) normal shock waves, (b) oblique shock waves, and (c) Prandtl–Meyer expansion waves?arrow_forwardEx: A combustion chamber consists of tubular combustors of 15-cm diameter. Compressed air enters the tubes at 550 K, 480 kPa, and 80 m/s. Fuel with a heating value of 42,000 kJ/kg is injected into the air and is burned with an air–fuel mass ratio of 40. Approximating combustion as a heat transfer process to air, determine the temperature, pressure, velocity, and Mach number at the exit of the combustion chamberarrow_forward
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