Air flows at 70°C with an average velocity of 9 L=10 m m/s through a 10 m long rectangular duct with a 20 cm x 35 cm cross section. If the walls of the Air duct are to be kept constant at 20°C determine 70°C 9 m/s the exit temperature of the air leaving this Ts = 20°C channel and the rate of heat transfer from the air. Also, calculate the power of the fan required to overcome the pressure losses in this duct.

Air flows at 70°C with an average velocity of 9 L=10 m m/s through a 10 m long rectangular duct with a 20 cm x 35 cm cross section. If the walls of the Air duct are to be kept constant at 20°C determine 70°C 9 m/s the exit temperature of the air leaving this Ts = 20°C channel and the rate of heat transfer from the air. Also, calculate the power of the fan required to overcome the pressure losses in this duct.

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.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.38P

See similar textbooks

Similar questions

6.1 Determine the heat transfer coefficient at the stagnation point and the average value of the heat transfer coefficient for a single 5-cm-OD, 60-cm-long tube in cross-flow. The temperature of the tube surface is , the velocity of the fluid flowing perpendicular to the tube axis is 6 m/s, and the temperature of the fluid is . Consider the following fluids: (a) air, (b) hydrogen, and (c) water.
Air at 1atm, 35 degree celcius (ρ = 1.145 kg/m3 and μ = 1.895 x 10-5 kg/m.s) and average velocity of 7 m/s, enters a 10m section of a circular pipe with diameter of 20cm. Neglecting the entrance effects, determine the fan power needed to overcome the pressure losses in the duct. Use friction factor f= 0.020336
Glycerin at 40°C with ? = 1252 kg/m3 and ? = 0.27 kg/m·s is flowing through a 6-cm-diameter horizontal smooth pipe with an average velocity of 3.5 m/s. Determine the pressure drop per 10 m of the pipe.
Consider the flow of oil with ? = 894 kg/m3 and ? = 2.33 kg/m·s in a 28-cmdiameter pipeline at an average velocity of 0.5 m/s. A 330-m-long section of the pipeline passes through the icy waters of a lake. Disregarding the entrance effects, determine the pumping power required to overcome the pressure losses and to maintain the flow of oil in the pipe.
Air enters a 7-m-long section of a rectangular duct of cross section 15 cm X 20 cm at 50°C at an average velocity of 7 m/s. If the walls of the duct are maintained at 10°C, determine: (a) the outlet temperature of the air, (b) the rate of heat transfer from the air, and (c) the fan power needed to overcome the pressure losses in this section of the duct.
The 100-mmmm-diameter pipe is connected by a nozzle to a large reservoir of air that is at a temperature of 60 ∘C∘C and absolute pressure of 550 kPakPa . The backpressure causes M1>1M1>1, and the flow is choked at the exit, section 2, when L� = 5 mm. Assume a constant friction factor of 0.0085 throughout the pipe. Gas constant for air is R� = 286.9 J/[kg⋅K]J/[kg⋅K] and its specific heat ratio is k� = 1.40. (Figure 1) Determine the mass flow through the pipe. Express your answer using three significant figures.
Consider an air solar collector that is 1 m wide and 5 m longand has a constant spacing of 3 cm between the glass cover andthe collector plate. Air enters the collector at 30°C at a rate of0.15 m3/s through the 1-m-wide edge and flows along the 5-mlong passage way. If the average temperatures of the glasscover and the collector plate are 20°C and 60°C, respectively,determine (a) the net rate of heat transfer to the air in thecollector and (b) the temperature rise of air as it flows throughthe collector.
a rectangular duct made of commercial steel is used to channel air at 1 atm and 35°C at an avergae velocity of 7m/s. The duct is 15 cm by 20 cm and 12m long. Disregarding the entrance effects, determine the fan power needed to overcome the pressure losses in this section of the duct.
Water at 10°C (? = 999.7 kg/m3 and ? = 1.307 × 10−3 kg/m·s) is flowing steadily in a 0.12-cm-diameter, 15-m-long pipe at an average velocity of 0.9 m/s. Determine (a) the pressure drop, (b) the head loss, and (c) the pumping power requirement to overcome this pressure drop.
A rectangular duct made of commercial steel is used to channel air at 1 atm and 35°C at an average velocity of 7 m/s. The duct is 15 cm by 20 cm and 12 m long. Disregarding the entrance effects, determine the fan power needed to overcome the pressure losses in this section of the duct.
Water at 15°C is to be heated to 65°C by passing it over a bank of resistance heating rods 4 m long and 1 cm in diameter which are maintained at 90°C. The water is approached by the heater rod bank at the normal direction at an average speed of 0.8 m/s. The rods are arranged in line with longitudinal and transverse steps of SL = 4 cm and ST = 3 cm.Determine the number of rows of NL tubes in the direction of flow needed to achieve the indicated temperature rise. I need the solution from fundamental concepts of how the heat flow behaves in the system
Air enters a 12-cm-diameter adiabatic duct with inlet conditions of V1 = 150 m/s, T1 = 500 K, and P1 = 200 kPa. For an average friction factor of 0.014, determine the duct length from the inlet where the inlet velocity doubles. Also determine the pressure drop along that section of the duct.