Air at 20°C enters a heated circular tube with a diameter of 30 mm and a length of 3 m. The mass flow rate is 0.005 kg/s and the flow is fully developed with h = 25 W/m². 20°C 0.005 kg/s q" If the tube is heated by uniform surface heat flux of 1000 W/m², calculate the surface temperature at the outlet (Ts.o) in °C =
Q: A gas is cooled by circulating it in a turbulent regime through the interior of a circular duct with…
A: Given: The diameter of duct, Di = 0.025 m The internal wall temperature, Ti = 310 K The average…
Q: Hot carbon dioxide exhaust gas at 1 atm is being cooled by flat plates. The gas at 220°C flows in…
A: Given data: *The hot carbon dioxide is at 1 atm pressure. *The temperature of the gas is Tg=220°C.…
Q: Q8) A 0.4 W cylindrical electronic component with diameter 0.3 cm and length 1.8 cm and mounted on a…
A:
Q: Water (5.0 L/min) is flowing in a tube "D = 3 cm, L= 5 m" and is to be heated from 15°C to 64.0°C by…
A:
Q: Air at 1 atm and 20°C flows in a 3-cm-diameter tube. The maximum velocity of air to keep the flow…
A:
Q: Air flows through a 10 cm internal diameter tube at the rate of 75 kg/hr. Measurements indicate that…
A:
Q: A7 To a 5ft long ½” ID pipe that is maintained at a uniform temperature of 150ºF oil enters at 70ºF…
A: Given: The diameter of the pipe, d = ½ in = 0.04166 ft The length of the pipe, L = 5 ft The…
Q: Air enters a 12-m-long, 5-cm-diameter adiabatic duct at V1 = 70 m/s, T1 = 500 K, and P1 = 300 kPa.…
A: Given data: *The air length of the duct is L=12 m. *The diameter of the duct is d=5 cm. *The…
Q: A 4-m x 4-m flat plate maintained at a constant temperature of 80°C is subjected to parallel flow of…
A:
Q: Air enters a 25-cm-diameter 12-m-long underwater duct at 50°C and 1 atm at a mean velocity of 7 m/s,…
A: Given data as per question Diameter of duct = 25 cm Length of the duct =12 m Velocity = 7 m/s Air…
Q: Water flows at 1 kg/s in a 10 mm diameter tube and is to be heated from 25 to 75 °C. The tube…
A: INTRODUCTION : When a flowing fluid travels through a heat exchanger, our focus is on either cooling…
Q: For air flow at a constant wall temperature of 100 ◦C and average bulk temperature of 40 ◦C through…
A: Tb=40°CV=0.8m/sD=4cm=0.04m h=?
Q: A 1.2-in-outer-diameter pipe is to span across a river at a 115-ft-wide section while being…
A: Given: The outer diameter of the pipe is D=1.2 in. The width of the river is W=115 ft. The average…
Q: What are the three layers within turbulent flow? In which layer is the velocity smallest and in…
A: The three layers within the turbulent flow are: 1. Wall layer - This is the layer near the boundary…
Q: Water at 10°C is flowing steadily in a 0.12 cm diameter, 15 m long horizontal pipe at an average…
A: For solution refer below images.
Q: EES Metal plates (k = 180 W/m-K, p= 2800 kg/m², |and c, = 880 J/kg-K) with a length of 1 m and a…
A:
Q: Saturated water at 50° C flows over a 150 cm long flat plate with a velocity of 3 m/s. The plate…
A:
Q: 2. The velocity and temperature profiles of the fluid flowing under laminar flow condition in a pipe…
A: Flow parameters such as velocity temperature discharge are the defining values in fluid dynamics.…
Q: The components of an electronic system are located in a 1.5-m-long horizontal duct whose cross…
A: given data Length of the pipe L = 1.5m Cross section area of the duct = 0.2*0.2 m2 Temperature of…
Q: Hot methane exhaust gas at 1 atm is being cooled by flat plates. The gas at 150°c flows parallel…
A: Assuming that hot methane acts as air.
Q: Q10) A1.8 m-diameter spherical tank of negligible thickness contains iced water at 0°C. Air at 25°C…
A: To find: The rate of heat transfer to the tank. Given: The diameter of tank is 1.8 m. The…
Q: Example 2: The local atmospheric pressure in Denver, Colorado (elevation 1610 m), is 83.4 kPa. Air…
A:
Q: Air is flowing in a 0.2-m-diameter pipe at a uniform velocity of 0.1 m/s. The temperature is 25°C…
A: Data given- D = 0.2 m V= 0.1 m/s T = 25°C P = 150 kPa
Q: When the compressibility effects become significant in heat transfer problems in high speed flow
A: The Mach number is used to estimate how close a flow may be considered as an incompressible…
Q: In a geothermal power plant, the used geothermal water at 80°C enters a 15-cm-diameter and…
A: The average film temperature is written as, The properties of the air at this average film…
Q: A tube bank uses a staggered arrangement of D=0.9 cm diameter tubes with S,=2 cm and S=1.5 cm. There…
A:
Q: Hot carbon dioxide exhaust gas at 1 atm is being cooled by flat plates as shown in Fig 3. The gas at…
A:
Q: In the effort to increase the removal of heat from a hot surface at 120°C, a cylindrical pin fin (kf…
A: The properties of air at a temperature of 70 oC are given as, The characteristic length of the…
Q: Hot air at 1 bar and 80 degree Celcius enters a 8 m long uninsulated square duct of cross-section 20…
A:
Q: A computer cooled by a fan contains eight printed circuit boards (PCBs), each dissipating 10 W of…
A: (a) Given, the bulk temperature of air should be assumed as 25°C. Therefore, write the values of…
Q: Water (5.2 L'min) is flowing in a tube "D-3 cm, L-5 m" and is to be heated from 15°C to 59.9°C by…
A: Given:Volume Flow rate,Q=5.2Lmin=5.2×10-360m3secDiameter,D=3cm=0.03mLength of tube,L=5mInitial…
Q: Air at a pressure of 1 atm. abs. and 50°C flows parallel to the top surface of a rectangular plate,…
A:
Q: Heated air at 1 atm and 35°C is to be transported in a 150-meter long circular plastic duct at a…
A:
Q: How is the Reynolds number related to Darcy-Weisbach?
A: Reynolds number is used to determine the nature of the fluid, Laminar or turbulent fluid.
Q: A 1.2-in-outer-diameter pipe is to span across a river at a 140-ft-wide section while being…
A: Given data as per question Diameter of pipe =1.2 in Flow velocity = 10ft/s
Q: Hot carbon dioxide exhaust gas at 1 atm is being cooled by flat plates. The gas at 220oC flows in…
A:
Q: Air enters a 10-m-long section of a rectangular duct of cross section 15 cm * 20 cm made of…
A: Calculating hydraulic diameter of the duct,
Q: Consider air with mass flow rate of 1 g/s entering a tube with diameter D=5 mm, length L=x2- Xq=750…
A: When an object is hotter or colder than the surrounding fluid, convective heat transfer takes place.…
Q: Q7) The components of an electronic system are located in a 1.5-m-long horizontal duct whose cross…
A:
Q: The components of an electronic system are located in a 1.8-m-long horizontal duct whose cross…
A: Given:- Ts=65 T∞=30 k=0.02717W/m.k v=1.744*10-5m2/s Pr=0.72345 V=200m/min D=20cm To Find:- The total…
Q: Determine the terminal velocity of a 100 mm diameter cylinder, having a length of 360 mm and…
A:
Q: The local atmospheric pressure in Denver, Colorado (elevation 1610 m), is 83.4 kPa. Air at this…
A: (a) The average temperature is written as, The properties of air at this temperature are given as,…
Q: Water enters a heated circular tube with a diameter of 25.4 mm and a length of 5 m. The water…
A: Given: Diameter of the tube (D)=25.4mm Length of the tube (L)=5m Water velocity (V)=0.6m/s Inlet…
Q: Air flows over a flat plate at a constant velocity of 20 m/s and ambient conditions of 20 kPa and…
A:
Q: What fluid property is responsible for the development of the velocity boundary layer? For what…
A: The viscosity is the property which is responsible for the development of the velocity boundary…
Q: Air is heated in a 4cm×4cm sheet metal duct with a uniform surface heat flux of 590 W/m2. The mean…
A:
Heat Transfer
Question is image
Step by step
Solved in 2 steps with 2 images
- 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= 0.020336Hot air (43 °C) at 1 atm flows into a circular plastic duct 50 m long at a rate of 0.2 m3/s. If the friction loss, hL, in the pipe does not exceed 6 m. Determine the diameter of the duct, the velocity of the fluid, and the Reynolds number.
- 1) Atmospheric air at 25oC and with a speed of 50 m/s is pumped by a fan over a flat plate. a)What is the minimum plate length in order to achieve a Reynolds number of 108 ? b)At what distance from the leading edge would transition occur if critical Re #= 5x105 ? 2) Local Nusselt number is given as Nux=0.04Rex0.9 Pr 1/3. Obtain an expression for, a) average heat transfer coefficient, x b) local heat transfer coefficient, hx c) What is the ratio of the average to local coefficient, x / hx 3) Air is in parallel flow over a flat heater surface which is to be maintained at 140oC. Airflow induces a drag force of 0.25 N on the heater. What is the electrical power needed to maintain the prescribed surface temperature? 4) Air at 1 atm with a velocity of 4 m/s and a temperature of 50oC flows over a flat plate that is at a uniform temperature of 100oC. The plate has a length of 0.20 m and a width of 0.1 m. a) What is the average heat…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.Air enters a 25-cm-diameter 12-m-long underwater duct at 50°C and 1 atm at a mean velocity of 7 m/s, and is cooled by the water outside. If the average heat transfer coefficient is 85 W/m2?K and the tube temperature is nearly equal to the water temperature of 10°C, determine the exit temperature of air and the rate of heat transfer. Evaluate air properties at a bulk mean temperature of 30°C. Is this a good assumption?
- A desktop computer is to be cooled by a fan. The electronic components of the computerconsume 60 W of power under full load conditions. The computer is to operate inenvironments at temp. up to 45° C and at elevations up to 3400 m where the averageatmospheric pressure is 66.63 KPa, air density at this condition 0.73 kg/m³. The exit temp. ofair is not to exceed 60° C, air density of 0.7 kg/m³, to meet reliability requirements. Also theaverage velocity of the air is not to exceed 110 m/min at the exit of the computer case wherethe fan is installed to keep the noise level down. Assume that there is an increase in internalenergy of 10.779 kj/kg. Determine the flow rate of the fan that needs to be installed and thediameter of the casing of the fan.For a fixed compressor inlet velocity and flow area, explain the effect of increasing compressor inlet temperature (i.e., summertime operation versus wintertime operation) on the inlet mass flow rate and the net power output with all other parameters of the problem being the same.Water at 10°C (ρ = 999.7 kg/m3 and μ = 1.307 × 10−3 kg/m·s) is flowing steadily in a 5 -cm- diameter, 20-m-long circular stainless steel pipe. Determine(a) for a pressure drop of 10 KPa, what would the volumetric flow rate be?
- Two water reservoirs A and B are connected through a 40-m long, 2-cm diameter cast iron pipe with a sharp-edged entrance. The pipe also involves a swing check valve and a fully open gate valve. The water level in both reservoirs is the same, but reservoir A is pressurized by compressed air while reservoir B is open to the atmosphere at 88 kPa. The water temperature is 10°C. a. If the initial flow rate through the pipe is 1.2 L/s, determine the absolute air pressure on top of reservoir A. b. Determine the pressure just before the valveAir at 60°C leaves a furnace and passes through a 12-m long, 20-cm × 20-cm square duct at an average velocity of 4 m/s. If the duct has a constant surface temperature of 33°C, determine the exit temperature of the air and the rate of heat transfer.The compressed air requirements of a textile factory are met by a large compressor that draws in 0.6 m3/s air at atmospheric conditions of 20°C and 1 bar (100 kPa) and consumes 300 kW electric power when operating. Air is compressed to a gage pressure of 8 bar (absolute pressure of 900 kPa), and compressed air is transported to the production area through a 15-cm-internal-diameter, 83-m-long, plastic (smooth) pipes with a surface roughness of 0.15 mm. The average temperature of compressed air in the pipe is 60°C. The compressed air line has 8 elbows with a loss coefficient of 0.6 each. In order to reduce the head losses in the piping and thus the power wasted, someone suggests doubling the diameter of the 83-m-long compressed air pipes. Calculating the reduction in wasted power, and determine if this is a worthwhile idea. Considering the cost of replacement, does this proposal make sense to you?