2. Experiments have shown that, for airflow at T=35°C and V1= 100 m/s, the rate ofheat transfer from a turbine blade of characteristic length L₁ = 0.15 m and surfacetemperature Ts,1=300°C is q1=1500 W. What would be the heat transfer rate froma second turbine blade of characteristic length L2 = 0.3 m operating at Ts,2=400°Cin airflow of Tx-35°C and V2 = 50 m/s? The surface area of the blade may beassumed to be directly proportional to its characteristic length.Answer: 2066W

Answered: 2. Experiments have shown that, for…

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.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.31P

See similar textbooks

Similar questions

A 1-in-diameter (D = 1 inch) rotating machined shaft has a groove 0.1-in deep with a 0.1-in radius machined into it. The shaft is subjected to a pulsating (i.e. R = 0) torque and bending moment of following values. Based on laboratory experiments at 550°F, Sut = 150 ksi, Sy = 120 ksi, and S'e = 90 ksi are measured. Using mod-Goodman equation and for operating temperature of 550°F and 90% reliability, determine the factor of safety for yielding and fatigue of this shaft. Tmax = 2000 Ib-in Mmax = 1600 lb-in Mmin = -1200 Ib-in D - -d- M T M T
The liquid food is flowed through an uninsulated pipe at 90 ° C. The product flow rate is 0.3 kg / s and has a density of 1000 kg / m³, specific heat 4 kJ / (kg K), a viscosity of 8 x 10-6 Pa s, and a thermal conductivity of 0.55 W / (m) K). Assume that the change in viscosity is negligible. The internal diameter of the pipe is 30 mm with a thickness of 3 mm made of stainless steel (k = 15 W / [m ° C]). The outside temperature is 15 ° C. If the outer convective heat transfer coefficient is 18 W / (m² K), calculate the heat loss at steady state per meter pipe length. a. Find the convection coefficient in pipe = W / m² ° C. b. Calculate heat loss per meter pipe length = watts
You are using hard chromium electroplating on the rod of a very large hydraulic cylinder. Air at a temperature of 18°C (P = 1 atm) and a velocity of 18.2 m/sec flows in cross-flow over the circular rod that was just removed from the electroplating process. The rod has a diameter of 0.15 m, is 1.45 m long, and is at a temperature of 62°C. a) Find the heat transfer rate from the rod to the air (q). b) Calculate the drag force on the rod due to the air flow.
A 4.5 in (inside diameter), 4.9 in (outside diameter) tube carries dry saturated steam at 10 bar. Assume that the interior temperature of the tube is the same as that of the steam. The outside air temperature is 25°C. For ksteel = 51.9 W/(m K) and hair = 13.0 W/(m2K). a) How much energy is lost, in kWh, in a 20 m long section of pipe during an 8-hours
The liquid food is flowed through an uninsulated pipe at 90 ° C. The product flow rate is 0.4 kg / s and has a density of 1000 kg / m³, specific heat 4 kJ / (kg K), a viscosity of 8 x 10-6 Pa s, and a thermal conductivity of 0.55 W / (m) K). Assume that the change in viscosity is negligible. The internal diameter of the pipe is 20 mm with a thickness of 3 mm made of stainless steel (k = 15 W / [m ° C]). The outside temperature is 15 ° C. If the outer convective heat transfer coefficient is 18 W / (m² K), calculate the heat loss at steady state per meter of pipe length. a.Find the convection coefficient in the pipe = AnswerW / m² ° C. b. Calculate heat loss per meter pipe length = Answerwatt.
Control volume concept can be used to obtain forces in both internal and external flow. By drawing a control volume around a region of fluid to expose the stresses acting on the boundaries and applying the conservation of mass and conservation of momentum in integral form, the net forces acting on the fluid and hence the reaction forces acting on the solid boundary can be calculated. The advantages of this approach over differential approach are: (i) It is an easy way to obtain net forces. (ii) It gives a detailed understanding of how these forces are generated. (iii) It is commonly used in engineering practice to obtain reaction forces on pump, turbine, elbow, etc. for the design of anchoring fixtures/foundation. (A) (B) (C) (D) (i) and (ii) (i) and (iii) (ii) and (iii) All of the above
A circuit board is cooled by passing cool helium gaş "C,= 5193 J/kg.C, v =1.233×10 m /s, p= 0.1635 kg/m Pr = 0.669, k = 0.1565 W/m.°C " through a channel [0.46 cm x14 cm×20 cm ] drilled into the board. Helium enters at 15°C and 6.8 m/s and leaves at 63.7 °C. The heat flux at the top surface of the channel can be considered to be uniform, and heat transfer through other surfaces is negligible. Assume fully developed flow for the whole channel length and (if flow is NOT Laminar use Dittus-Boelter equation:Nu=0.023 Re Pr) What is the maximum surface temperature on the circuit board (°C)? Electronic components, T, °C Не 15°C L=20 cm Channel
(heat transfer)
Answer this ASAP The diameter of the tube is 25 mm. The specific heat of water is 4.18 kJ/kg.°C. The overall heat transfer coefficient is 0.7 kW/m².°C. 1. Schematic of temperature distribution 2.ΔTLMTD 3.Actual heat transfer rate 4.Cmin 5.Maximum heat transfer rate
Air at atmospheric pressure and temperature of 25 oC flows at a speed of 10 m/s along a flat plate that is 4 m long and has a uniform surface temperature of 140 oC. Ifcritical Reynolds number of 200,000:a) the local heat transfer kingdom at x = 2; 3; and 4 m from the front rim.b) the average heat transfer balance is 4 m long.c) the rate of heat transfer from the surface of the plate to the air if the width of the plate surface is 2 m.d) game problems b) and c) flow velocity 5 and 20 m/se) What is your analysis and conclusion on this case?
Forced air at T0 = 25°C and V = 17 m/s is used to cool electronic elements on a circuit board. One such element is a chip, 4 mm x 4 mm, located 129 mm from the leading edge of the board. Experiments have revealed that flow over the board is disturbed by the elements and that convection heat transfer is correlated by an expression of the form Nuz = 0.04RE0.85 Pr3 V, T. Chip Board L mm Estimate the surface temperature of the chip if it is dissipating 38 mW.
Pinch temperature at hot stream is 70C, while at cold stream is 60C

SEE MORE QUESTIONS

Recommended textbooks for you

Principles of Heat Transfer (Activate Learning wi…

Mechanical Engineering

ISBN:

9781305387102

Author:

Kreith, Frank; Manglik, Raj M.

Publisher:

Cengage Learning