Question

What does Nusselt number equals? Show that it is the dimensionless temperature gradient at the wall,...

What does Nusselt number equals? Show that it is the dimensionless temperature gradient at the wall, in the process of external convection heat transfer.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A flat wall is exposed to an environmental temperature of 38 degrees C. The wall is...
A flat wall is exposed to an environmental temperature of 38 degrees C. The wall is covered with a layer of insulation 2.5 cm thick whose thermal conductivity is 1.8 W/(m.K), and the temperature of the wall on the inside of the insulation is 320 degrees C. The wall loses heat to the environment by convection. Compute the value of the convection heat transfer coefficient that must be maintained on the outer surface of the insulation to ensure that the...
A hot black painted pipe(2.54-cmO.D.and50-mlong)passesthrougha 20°C room to heat it. The temperature of the pipe surface...
A hot black painted pipe(2.54-cmO.D.and50-mlong)passesthrougha 20°C room to heat it. The temperature of the pipe surface is 150°C. If the heat transfer coefficient by convection to the air is 10 W/m2-K : a) What is the total heat rate loss? b) What is the radiation heat transfer coefficient? c) At what temperature of the pipe, the heat rate by convection equals the heat rate by radiation.
Air at freestream velocity U∞=16 ms, and free steam temperature      T∞=50℃ is flowing over a plate...
Air at freestream velocity U∞=16 ms, and free steam temperature      T∞=50℃ is flowing over a plate surface that is at temperature Ts=100℃. The velocity and thermal boundary layers developing on the surface have been shown in the figure. Also shown are the tangents to the velocity and temperature profiles at the surface y=0. If the density of air is ρ∞=1.1 kgm3, viscosity μ=1.963×10-5kgm∙s, and thermal conductivity k=0.0274Wm∙K then, calculate (a)        the wall shear stress, τw (b)       coefficient of skin friction,...
Why is a temperature gradient used in gas chromatography? What effect does increasing the temperature have...
Why is a temperature gradient used in gas chromatography? What effect does increasing the temperature have on eluting compounds?
Air is flowing at a Mach number of M = 0.8 and a temperature of 35...
Air is flowing at a Mach number of M = 0.8 and a temperature of 35 Celsius. What temperature would the air be if it were brought to rest with no external work or heat transfer?
Water at 15°C enters a tube of 2 cm of diameter with flow rate 3953 kg/h....
Water at 15°C enters a tube of 2 cm of diameter with flow rate 3953 kg/h. Assume the ratio L/D>10, and the wall temperature is constant at 80-C. The outlet temperature is 50°C The properties of water at the film temperature are density rho = p = 985 kg/m3, specific heat Cp = 4180 J/kgk, conductivity k = 0.651 W/mK, dynamic viscosity mu= u = 4.71 × 10- kg/ms, At the wall temperature of 80°C we have dynamic viscosity muw=...
Select the option that is false: a) A small number of Biot represents little resistance to...
Select the option that is false: a) A small number of Biot represents little resistance to heat conduction and, therefore, small temperature gradients within the body. b) The Fourier number is a measure of the heat conducted through a body in relation to the stored heat. c) None of the other options is false d) The Prandtl number does not depend on the type of flow and its geometric configuration e) The Biot number compares the transfer of thermal energy...
Heat and mass transfer question: Why blackbody does not exist? What if there is a "blackbody"...
Heat and mass transfer question: Why blackbody does not exist? What if there is a "blackbody" in outer space without any contact to any object, so no conduction no convection, can I emit its 100% energy? Why not?
A thin metallic wall may be constructed using copper (properties are given in the table). The...
A thin metallic wall may be constructed using copper (properties are given in the table). The piping is required to have a radius r = 0.008 m and carries steam at 385 K. The wall is inside a room surrounded by air at a temperature of 298 K. The wall is insulated with a material (properties are given in the table). Properties Copper Insulation material Thermal Conductivity (W/m per ˚C) 385 0.071 Density (kg/m3) 8940 453 i. If the external...
1.What is the relationship between the change in length and change in temperature of a body?...
1.What is the relationship between the change in length and change in temperature of a body? 2. When is a system considered to be in thermal equilibrium? When does heat transfer from one body to another stop? 3. Where does the amount of heat absorbed by ice go if its temperature remains the same?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT