12. Start with Equation IVb.2.8 and obtain Equation IVb.2.9. For this purpose, first ignore the non-linear term compared with the two dominant terms. Then sub- stitute for the velocity and temperature profiles. To develop the integral, consider a case where the hydrodynamic boundary layer is thicker than the thermal bound- ary layer (thus the integral is zero for y > 8'). Arrange the result in terms of = 8'18 and ignore *.

12. Start with Equation IVb.2.8 and obtain Equation IVb.2.9. For this purpose, first ignore the non-linear term compared with the two dominant terms. Then sub- stitute for the velocity and temperature profiles. To develop the integral, consider a case where the hydrodynamic boundary layer is thicker than the thermal bound- ary layer (thus the integral is zero for y > 8'). Arrange the result in terms of = 8'18 and ignore *.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter6: Forced Convection Over Exterior Surfaces

Section: Chapter Questions

Problem 6.21P

See similar textbooks

Similar questions

Air at 1.7 atm gauge and 15°C enters a horizontal 75-mm steel pipe that is 70 m long. The velocity at the entrance of the pipe is 60 m/s. Assuming isothermal flow, what is the pressure at the discharge end of the line?
Hint: Assume your own initial conditions
You are being tasked as a wind tunnel engineer to investigate the performance of newly designed high-speed wind tunnel in UPNM. An exhaust gas flows through a nozzle where the inlet area is 5,000 cm2.At this inlet, the gas has a velocity of 1,200 m/s, temperature of 1,500oC,and pressure of 6,000 kPa. Initial measurement revealed that the pressure at the exit of the wind tunnel is 100 kPa. Based on this information, analyze and investigate ; i. Mach number at inlet of the nozzle ii. The velocity of gas at exit iii. The area of the nozzle at exit Take specific heat ratio for the exhaust gas, ? to be 1.7 and the gas constant, R to be 205 J/kg.
Example: A fan of diameter 0.7 m running 1500 rpm delivers 140 m3/min of air at 15C against 75 mm of water total pressure when the total effeciency is 86%. Determine the volume of air delivered, total pressure and power consumed, if (a) the air temperature is 50C. (b) the air temperature is 50C and the fan speed is 1700 rpm. (c) the same conditions as (b) but a 0.6 m diameter, geometrically similar fan is used.
A laminar boundary layer is observed to grow on a flat plate such that the pressure is constant everywhere. If the boundary layer velocity profile is given by: where u is the velocity at a distance y from the surface, δ is the boundary layer thickness and Ue is the freestream velocity. (a) Show that θ/δ = 0.139, where θ is the momentum thickness. (b) Find the viscous stress on the plate in terms of the viscosity, the boundary layer thickness, and the freestream velocity.
The shock waves on a vehicle in supersonic flight cause a component ofdrag called supersonic wave drag Dw. Define the wave-drag coefficient asCD,w = Dw/q∞S, where S is a suitable reference area for the body. Insupersonic flight, the flow is governed in part by its thermodynamicproperties, given by the specific heats at constant pressure cp and atconstant volume cv. Define the ratio cp/cv ≡ γ . Using Buckingham’spi theorem, show that CD,w = f (M∞, γ ). Neglect the influence of friction.
When viscous dissipation is appreciable, the energy balance of a convective system must include the viscous effects of the fluid, so a third term is added to the energy balance: A slide bearing (pillow block) can be idealized as a static plate and a plane that moves parallel to it. The rotary axis of such a system has a diameter of 100 mm and rotates at 3600 rpm inside the bearing, which has a gap between the plates of 0.5 mm. The system is lubricated by oil, with a density of 800 kg / m, a viscosity of 0 01 kg / ms and a thermal conductivity of 0:14 W / mk. The top and bottom surfaces of the bearing are at 60 ° C. Considering the viscous effects of the oil, determine a) The maximum temperature of the oil. FC b) Bottom plate heat flux per unit length W / m Write down all assumptions made
A steam generator generates flue gas at an average temperature of 260 C inside a Chimney. The theoretical draft is 0.5 kPa and the ambient condition of the air is 21 C and 100 kPa. Assume the coefficient velocity to be 0.30 and the molecular weight of the flue gas is 32. For air-fuel ratio requirements per second of 15, calculate: a. The diameter of the Chimney, meter b. The theoretical draft, cm H₂O
Show complete solution: Establish and simplify the mass and energy balance equations for a fluid of constant density flowing at steady-state through a straight pipe of constant diameter D and length L. What are your thoughts regarding the simplified forms of the balance equations?
Derive the steady flow equation from first principles
One type of supersonic wind tunnel is a blow-down tunnel, where air is stored in a high-pressure reservoir, and then, upon the opening of a valve, exhausted through the tunnel into a vacuum tank or simply into the open atmosphere at the downstream end of the tunnel. For this example, weconsider just the high-pressure reservoir as a storage tank that is being charged with air by a high-pressure pump. As air is being pumped into the constant-volume reservoir, the air pressure inside the reservoir increases. The pump continues to charge the reservoir until the desired pressure is achieved.Consider a reservoir with an internal volume of 30 m3. As air is pumped into the reservoir, the air pressure inside the reservoir continually increases with time. Consider the instant during the charging process when the reservoir pressure is 10 atm. Assume the air temperature inside the reservoir is held constant at 300 K by means of a heat exchanger.Air is pumped into the reservoir at the rate of 1…
A saturated steam at 410K is being transported in a pipeline (brass drawing tubing) at a rate of 1 grams/second. Pipe has inside diameter of 0.025 m . The tube is 100m long. The pressure at the entrance is 80kPa. (use Perry's Handbook for the properties and constants) R = 8314J/kgmol.K; MW=18.02g/mol What is the a.) value of G in kg/s.m2? b.)value of friction factor? 3 significant figures c.)the % of pressure drop? d.)the outlet pressure? e.) compressible or not?