Hot water at an average temperature of 80°C and an average velocity of 1.5 m/s is flowing through a 25-m section of a pipe that has an outer diameter of 5 cm. The pipe extends 2 m in the ambient air above the ground, dips into the ground (k= 1.5 W/m-°C) vertically for 3 m, and continues horizontally at this depth for 20 m more before it enters the next building. The first section of the pipe is exposed to the ambient air at 8°C with a heat transfer coefficient of 22 W/m2.°C. If the surface of the ground is covered with snow at 0°C, determine: (a) Heat loss from the part of the tube that is on the ground. (b) Heat loss for vertical part of the tube. The shape factor, and the rate of heat loss on the horizontal part that is in the ground.

Hot water at an average temperature of 80°C and an average velocity of 1.5 m/s is flowing through a 25-m section of a pipe that has an outer diameter of 5 cm. The pipe extends 2 m in the ambient air above the ground, dips into the ground (k= 1.5 W/m-°C) vertically for 3 m, and continues horizontally at this depth for 20 m more before it enters the next building. The first section of the pipe is exposed to the ambient air at 8°C with a heat transfer coefficient of 22 W/m2.°C. If the surface of the ground is covered with snow at 0°C, determine: (a) Heat loss from the part of the tube that is on the ground. (b) Heat loss for vertical part of the tube. The shape factor, and the rate of heat loss on the horizontal part that is in the ground.

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

A gardener is thinking of installing piping system for watering the plants in his garden located near a water reservoir. The reservoir is located at an elevation of 150 m above from the surface, as shown in figure. The diameter of pipe (cast iron) is constant equal to 15 cm and total length of pipe is 180 m. It is desirable that the exit velocity of water to the garden should not exceed 5 m/sec and water is at atmospheric pressure and temperature is 20°C. The gardener is planning to open the valve for 3 hours daily. Calculate the followings: a) How much volume of liquid can be drawn from reservoir in a day? b) How much total irreversible head loss will be occurred in the system?
Local Nusselt number for fully developed (hydrodynamically and thermally) turbulent flow in a smooth circular tube is defined by Nup-hD/kr, where h, D, and ke are the convective heat transfer coefficient, tube diameter, and fluid thermal conductivity, respectively. The friction factor for the smooth circular tube is given by the Blasius correlation, f-0.316Rep. The Reynolds number is defined by Ren-pviD/, where pr, vi, and ur are the fluid density, fluid velocity, and fluid viscosity, respectively. The Blasius correlation is applicable to Rep<2×10¹. Considering the analogy between velocity and thermal boundary layers and using the Blasius correlation, express the local Nusselt number using Reynolds and Prandtl numbers in the form of Nup-AxRepxPr. The Prandtl number is defined by Pr-wa, where and are the fluid kinematic viscosity and fluid thermal diffusivity, respectively. Note that the local Nusselt number formula should be applicable to Rep<2x10 and 0.6
A plate with negligible thickness of 50 cm and a length of 100 cm is exposed to 2 different air flows in the same direction from its lower and upper surface along its length. The speed of the air flowing from the upper surface of the plate is 3600 m / min and its temperature is 473 K, the temperature of the air flowing from the lower surface is 298 K and its speed is 600 m / min. Calculate the total heat exchange between both fluids. (Assume the initial temperature of the plate is 160⁰C.)
Air at atmospheric pressure flowing through a tube of 10 cm diameter at a rate of 0.1 kg/s is to be cooled from 400K to 300K with uniform wall temperature of 250K. Determine the length of the tube. Justify any assumptions that you have made.
Combustion gases passing through a 5-cm-internal-diameter circular tube are used to vaporize waste water at atmospheric pressure. Hot gases enter the tube at 225 kPa and 250oC at a mean velocity of 2.5 m/s, and leave at 150o If the average heat transfer coefficient is 150 W/m2K and the inner surface temperature of the tube is 110oC, determine (a) the tube length and (b) the rate of evaporation of water.
Water at 15°C (p = 999.1 kg/m3, cp = 4.18 kJ/kg.K and u = 1.138E-3 kg/m.s k = 0.631 W/m.°C) is flowing steadily in a 4.3-cm-diameter, 9.9- m-length horizontal pipe made of stainless steel at a rate of 1.9 kg/min, the outer surface is subjected, to a uniform heat flux of 6.2 kW/m". Assume fully developed flow. What is the pressure drop in the pipe "in Pascals"? Select one: А. 4.98 B. 5.62 С. 4.26 D. 3.53 O E. 6.26
Local Nusselt number for fully developed (hydrodynamically and thermally) turbulent flow in a smooth circular tube is defined by Nup-hD/kr, where h, D, and kr are the convective heat transfer coefficient, tube diameter, and fluid thermal conductivity, respectively. The friction factor for the smooth circular tube is given by the Blasius correlation, f-0.316Red ¹/4. The Reynolds number is defined by Rep-prviD/μr, where pr, vr, and ur are the fluid density, fluid velocity, and fluid viscosity, respectively. The Blasius correlation is applicable to Rep<2×10¹. Considering the analogy between velocity and thermal boundary layers and using the Blasius correlation, express the local Nusselt number using Reynolds and Prandtl numbers in the form of NuD-A-ReDxPr. The Prandtl number is defined by Pr-war, where and ar are the fluid kinematic viscosity and fluid thermal diffusivity, respectively. Note that the local Nusselt number formula should be applicable to Rep<2×10 and 0.6
Liquid sodium is to be heated from 500 K to 600 K by passing it at a flow rate of 5.0 kg/s through a 5-cm-ID tube whose surface is maintained at 620 K. What length of tube is required?
The wall of a furnace has an inner temperature of 500 F. The wall has a thickness of 2 inches and has a thermal conductivity of 0.02 Btu/(h·ft·F). On the outside, air at 30 F flows over the 10 ft x 10 ft wall at a speed of 10 ft/s. Determine the rate of heat loss from the furnace to the environment.
Harry up plz
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.
Consider a pipe with a length of 25 m and diameter of 5 cm. The surface temperature of the pipe is constant at 150°C.Oil at 20°C is passing though this pipe with a mass flow rate of 0.5 kg/s. determine (a) the temperature of the oil at the exit and (b) the total heat transfer rate. Note. Report your solution step by step and clearly.