Consider a concentric tube annulus for which the inner and outer diameters are 25 and
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Fundamentals of Heat and Mass Transfer
Additional Engineering Textbook Solutions
Introduction to Heat Transfer
DeGarmo's Materials and Processes in Manufacturing
Engineering Mechanics: Statics & Dynamics (14th Edition)
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
Degarmo's Materials And Processes In Manufacturing
Automotive Technology: Principles, Diagnosis, and Service (5th Edition)
- Water enters a tube of D=5-cm in diameter at Tmi=21°C with a flowrate of m=0.18- kg/min. The tube is wrapped with a resistance heater pad providing a constant heat flux of q'=2.4-kW/m?. Assuming that the flow is both hydrodynamically and thermally full developed, determine the length of the tube (in meters) required to heat the water to m,0=123 °C. Use the following.properties for the mean temperature of water: p=970.87 kg/m³, p=343×106N-s/m2 , k=0.671 W/m-K, cp=4200 J/kg-K, Pr=2.14.arrow_forwardTout=? V (m/s) D=0.1m air Air at (3.10x10^2) K is entering in a circular pipe at 101325 Pa as shown in Figure. The velocity of the air at the pipe entrance is (1.0000x10^O) m/s. The diameter of the pipe is 0.1m. Specific gas constant of air is 287 J/kg-K. Specific heat of air is 1000 J/kg-K. Find the outlet temperature if 2000 J of heat is added to the pipe. Answer should be in 'K' with three significant figures. Note: Your answer is assumed to be reduced to the highest power possible.arrow_forwardWater is pumped through an iron pipe (k=67.2 W/m2 K), 2 meters long as the rate of 1000kg/min. The inner and outer diameters of the tube are 50mm and 60mm respectively. Calculate the rise in temperature of water when the outside of the tube is heated to a temperature of 600°C. The initial temperature of the water is 30°C.arrow_forward
- Water (7.7 L/min) is flowing in a tube "D = 3 cm, L= 5 m" and is to be heated from 15°C to 62.1°C by applying a uniform heat flux on the outer surface of the tube by electric resistance heater. What is the power rating of the resistance heater (kW)? If turbulent flow use Dituss- Boetler relation Nu= 0.023 Re0.8 Pr". Properties : p = 992.1 kg/m³ , C, = 4179 J/kg.°C, k = 0.631 W/m°C, Pr = 4.32, v = 0.658E-6 m²/sarrow_forwarda] Steam at 280 oC, tube=26 W/m. It flows at a speed of 4.0 m/s along a pipe made of iron-steel material with a temperature of 0°C. The inner diameter of the iron-steel pipe is 6.0 cm and the outer diameter is 6.8 cm. In order to reduce the heat transfer, the iron-steel pipe is first covered with 2.0 cm thick glass wool (k = 0.38 W/m. oC), then with another 3.5 cm thick insulation material (k = 0.01 W/m. oC). The insulated iron-steel pipe is in the atmospheric environment where the temperature is 18 oC. The convective heat transfer coefficient on the outside atmospheric side of this pipe, where the steam flows, is 36 W/m2. oC, the film heat transfer coefficient on the steam side is 80 W/m2. Calculate the heat transferred per unit pipe length (W/m), since it is known to be °C. b] Calculate the thickness of the material when the pipe is sheathed externally with a material with a thermal conductivity of k=0.02 W/m.oC in order to reduce the heat to be transferred by 20% in the unit pipe…arrow_forwardQ=2000J Tout=? V(m/s) D=0.1m air Air at (2.95x10^2) K is entering in a circular pipe at 101325 Pa as shown in Figure. The velocity of the air at the pipe entrance is (1.5000x10^0) m/s. The diameter of the pipe is 0.1m. Specific gas constant of air is 287 J/kg-K. Specific heat of air is 100O J/kg-K. Find the outlet temperature if 2000 J of heat is added to the pipe. Answer should be in 'K' with three significant figures. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: Activate Windows Go to Settings to activat (? 9°C ENG 2020arrow_forward
- Engine oil is heated by flowing through a circular tube of Diameter D= 50 mm, length L= 25, and whose surface is maintained at 150 Deg. C. If the flow rate and inlet temperature of the oil are 0.5 Kg/s and 20 Deg.C Use the following properties: p= 852 kg/m³, o-u/p-37.5 x10-6 m²/s, k=138x10-3 W/m.K, Pr = 490, C₂= 2131 J/kg.K. u= px 0= 0.032 kg/m.s m = 0.5 kg/s Engine Oil Tml = 20 C DIA = 0.05 m 9 Ts = 150 C L = 25 m Tmo? Based on the above information. 1. Find Rep 2. Based on the value of Rep, what type of flow do we have? 3. Determine the outlet mean temperature Tm.o, with the average heat transfer coefficient = 33.12 W/m^2.Karrow_forwardQ=2000J Tout=? V(m/s) D=0.1m air Air at (3.050x10^2) K is entering in a circular pipe at 101325 Pa as shown in Figure. The velocity of the air at the pipe entrance is (1.50x10^0) m/s. The diameter of the pipe is 0.1m. Specific gas constant of air is 287 J/kg-K. Specific heat of air is 1000 J/kg-K. Find the outlet temperature if 2000 J of heat is added to the pipe. Answer should be in 'K' with three significant figures. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answer DELLarrow_forwardQ=2000J Tout=? V(m/s) D=0.1m air Air at (2.95x10^2) K is entering in a circular pipe at 101325 Pa as shown in Figure. The velocity of the air at the pipe entrance is (1.000x10^0) m/s. The diameter of the pipe is 0.1m. Specific gas constant of air is 287 J/kg-K. Specific heat of air is 1000 J/kg-K. Find the outlet temperature if 2000 J of heat is added to the pipe. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answerarrow_forward
- Water flows in a 3.5-cm-diameter pipe so that the Reynolds number based on diameter is 2000 (laminar flow is assumed). The average bulk temperature is 10°C. What would the heat transfer coefficient be in W/m2.°C for such a system if the tube wall was subjected to a constant heat flux and the velocity and temperature profiles were completely developed? Evaluate properties at bulk temperature.arrow_forwardWater is to be heated from 15 C to 65 C as it flows through a 3 cm internal diameter 5 m long tube. The tube surface is subjected to uniform heat flux. If the mean water velocity is 0.236 mm/s, determine 1. The total heat transferred to water. 2. The inner surface temperature of the pipe at the inlet and the exit. Take water properties p=992.1 kg/m³, v 0.658 x 10-6 m²/ s Cp=4179 J/kg.K, Pr-4.32, Nu= 0.023Re08Prº.4 k=0.631 W/m.°C,arrow_forwardWater enters a tube at 29°C with a flow rate of 460 kg/h. The rate of heat transfer from the tube wall to the fluid is given as qs′(W/m)=ax, where the coefficient a is 25 W/m2 and x(m) is the axial distance from the tube entrance. (a) Beginning with a properly defined differential control volume in the tube, derive an expression for the temperature distribution Tm(x) of the water. (b) What is the outlet temperature of the water for a heated section 31 m long? (c) Sketch the mean fluid temperature, Tm(x), and the tube wall temperature, Ts(x), as a function of distance along the tube for fully developed and developing flow conditions. (d) What value of a uniform wall heat flux, qs″ (instead of qs′=ax), would provide the same fluid outlet temperature as that determined in part 8.13b? For this type of heating, sketch the temperature distributions requested in part 8.13c.arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning