Cold air at 5°C enters a 19.1-cm-diameter 20-m-long isothermal pipe at a velocity of 1.8 m/s and leaves at 45°C. What is the convective heat transfer coefficient (W/m .K)? [p = 1.184 kg/m", c, = 1007 J/kg.K, k= 0.02551 W/m.K, v = 1.562 E-5 , Pr = 0.7296] Assume fully developed flow, if turbulent flow use Dittus-Boelter equation Nu = 0.023 Re Pr

Cold air at 5°C enters a 19.1-cm-diameter 20-m-long isothermal pipe at a velocity of 1.8 m/s and leaves at 45°C. What is the convective heat transfer coefficient (W/m .K)? [p = 1.184 kg/m", c, = 1007 J/kg.K, k= 0.02551 W/m.K, v = 1.562 E-5 , Pr = 0.7296] Assume fully developed flow, if turbulent flow use Dittus-Boelter equation Nu = 0.023 Re Pr

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Need answers in 30 minutes
Conceptually, what is the integral of heat transfer rate, Q dot?
An electric resistance heater is embedded in a long cylinder ofdiameter 30mm. When water with a temperature of 25 C and velocityof 1m/s flows crosswise over the cylinder, the power per unit lengthrequired to maintain the surface at a uniform temperature of 90 C is28kW/m. When air, also at 25 C, but with a velocity of 10m/s isflowing, the power per unit length required to maintain the samesurface temperature is 400W/m. Calculate and compare the convectioncoefficients for the flows of water and air.
Harry up plz
solve, show assumptions and full solutions
A horizontal thin plate with a length of L= 10 cm is tiled with a constant heat flux from the bottom and is cooled by air at the top. The air velocity is U = 40 m / s and the temperature is 20 ° C. What should be the minimum heat flux so that the plate temperature does not exceed 80°C? (kW / m²) v 17.94 x 10-6 m²/s = 0.0277 W/(m.K) Pr = 0.71
Water is flowving in a tube “D = 3 cm, L=5 m" and is to be heated from 15°C to 47°C by applying a uniform heat flux on the outer surface of the tube by electric resistance heater. If the Power rating is 11kW and the convective heat transfer coefficient is 864 W/m².K, what is the surface temperature at the exit “°C"? 3 Properties : p = 992.1 kg/m , C = 4179 J/kg.°C, k= 0.631 W/m°C, Pr = 4.32, v = 0.658E-6 m /s
B7
Hot air flows with a mass flow rate m = 0.09 kg/s through an uninsulated sheet metal duct of diameter D = 0.15 m, which is in the crawlspace of a house. The hot air enters at 110°C and, after a distance of L 5 m, cools to 80°C. The heat transfer coefficient between the duct surface and the ambient air at To 0°C is known to be h, = 9 W / m²K. (a) Calculate the heat loss from the duct over the length L. (b) Determine the heat flux and the surface temperature at x = L. (c) Determine the heat flux and the surface temperature at x = 0. Assume, for air at Tm 368 K: c, 1011 J/kg.K; for air at Tm.L = 353 K: k= 0.030 W/m.K, u = 209x10' N.s/m2, Pr = 0.70%; for air at Tm,0 = 383 K: k = 0.033 W/m.K, u=223x10" N.s/m2, Pr = 0.69. Show all calculations. Cold Air Hot air in -L-
Air at atmospheric pressure and 27oC is blown across a long 4.0-cm diameter tube at a velocity of20 m/s. Determine the heat transfer rate per unit length. Assume that the temperature of the wall is 60oC.
= 2562 J/kg.k, Pr 51.3, µ = 5.22E-3 Pa.s, k 0.260 W/m.K" flows at 0.9 kg/min inside a 3-mm diameter, thin- walled tube. The tube is coiled and Hot fluid %3D %3D %3D 00 submerged in a water bath maintained at 23°C. The fluid experiences a temperature drop of 65°C and leaves the tube at 35°C. What is the required length of the tube "m"? Neglect heat transfer · enhancement associated with the coiling. Assume fully developed flow, if turbulent flow use Dittus, Boelter equation: Nu = 0.023 Re 71 Pr. Select one: A. 18.40 B. 20.07 C. 21.98 D. 23.90 O E. 25.33 S PAGE NEXT PAGE nation
What is the length of tubing required to cool air from 80°C to 20°C via an isothermal tube maintained at 0°C? The tube diameter is 20 cm. Mean velocity of air is 4 m/s. Assume the flow to be fully-developed.