i need the answer quickly Answer all questions below:6.1Give 3 sources of error in the experiment?6.2Using your own word, explain what do you understand by convection?In which mode of heat transfer is the convection heat transfer coefficientusually higher, natural convection or forced convection? Why?6.36.4 What is natural convection? How does it differ from forced convection? Whatforce causes free convection currents?

Convection Convection consists of 2 mechanisms Energy transfer due to random molecular motion…

Answered: d the answe

Engineering

Mechanical Engineering

d the answe

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.54P

See similar textbooks

Similar questions

3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the atmosphere from outer space. If its original temperature is 38°C, the effective average temperature of the atmosphere is 1093°C, and the effective heat transfer coefficient is , estimate the temperature of the shell after reentry, assuming the time of reentry is 10 min and the interior of the shell is evacuated.
The heat transfer coefficient for a gas flowing over a thin float plate 3-m long and 0.3-m wide varies with distance from the leading edge according to hc(x)=10x1/4Wm2K If the plate temperature is 170C and the gas temperature is 30C, calculate (a) the average heat transfer coefficient, (b) the rate of heat transfer between the plate and the gas, and (c) the local heat flux 2 m from the leading edge. Problem 1.18
Air at 24°C is blown over a hot pipe with a surface area of 2.94 m2 to dissipate 924 W of heat energy. What is the minimum convection heat transfer coefficient that will ensure that the temperature of the pipe surface is less than 45°C [round your final answer to two decimal places]?
Write the appropriate Nusselt value for the each set of conditions provided below.1. Forced convection over a flat plate at constant qs. Calculated Re at mean temperature is 3500 and Pr= 0.7154. 2. Natural convection in a small holding tank with a heating element at the bottom. The calculated Ra number is 2.37 x10^93. Forced convection through an elliptical duct at constant Ts, where a/b=8. The temperature of the fluid at the inlet is higher than at the exit. Flow is fully developed with Re = 33370 and Pr= 0.693. 4. Natural convection over a sphere with Ra = 5 x 10^9 and Pr = 0.7362 PS. Do not round off intermediate values
Hab. Tiruneh, [4/2/2023 1:23 AM]A solar flux q ^ * falls on a unit length of a very thin tube of diameter d. Inside the tube is a stationary water with initial temperature T_{i} (same as ambient and no gradient inside at any time) and absorbs some of the heat while the rest leaves by convection from the surface to the ambient at T_{m} Develop an equation that can help to determine the temperature of the water at any time. Plot the temperature of the water against time. For a long elapsed time what will be the temperature? To simplify the analysis use theta = T*T_{e} * d*theta = dT theta_{i} = T_{i}*T_{o} (initial condition. Hab. Tiruneh, [4/2/2023 11:53 AM]A flat wall is exposed to an environmental temperature of 38°C. The wall is covered with a layer of insulation 2.5 cm thick whose thermal conductivity is 1.4W / (m ^2 *` C and the temperature of the wall on the inside of the insulation is 315°C. The wall loses heat to the environment by convection. Compute the value of the convection…
Solution on all other sites including this site are wrong Only attempt if previously not attempted. Answer part a and b A) Among the nondimensional numbers, in free convection, average Nusselt number depends on only Grashof and Prandtl numbers. only Grashof number. Rayleigh number. Reynolds number. B) For ideal gases, the specific heat capacity at constant pressure, thermal conductivity, dynamic viscosity, and Prandtl number are independent of pressure. How will the ratio of thicknesses of velocity boundary layer and thermal boundary layer change if pressure is increased from 1 atm to 5 atm for the flow of an ideal gas over a flat plate? We need to know the actual fluid properties to tell It will remain the same. It will decrease by a factor of 5. It will increase by a factor of 5.
Experiment No. (5) Heat Transfer, Power Input and Surface temperature Questions and Discussions 1. What is the difference between natural and forced convection heat transfer? 2. What sources of error are there in this experiment? 3. Mention the parameters you utilized during the calculation and discuss them briefly. 4. In what functions does Nusselt number in natural convection differ from forced convection, Discuss. 5. Give two examples of natural convection heat transfer. 6. In natural convetion, what makes the hot part of fluid to move?
Hello Sir,Good Evening. I have a question in my homework related Heat Transfer lesson. The following below is my question. Please Advice. Thank You "In the concept of convection heat transfer, the value of the convection coefficient (ℎ) is highly dependent on the flow velocity. Based on the concept (give a brief explanation)1. Which is more effective in transferring heat by natural convection or forced convection?2. How to explain the relationship between flow velocity and convection coefficient (ℎ) ?"
There is an equipment that allows to measure the heat transfer in fins with at least three different geometric shapes. To develop analysis skills among the students, the Heat Transfer teacher asks them to compare the performance of different cylindrical fins. These are "pin fins" made of aluminum (? = 200 W/m°C) and must be analyzed in terms of their relative performance as a function of diameter. Turning on the equipment, a base temperature of 200°C is recorded, the air temperature in the laboratory is T_∞= 20°C and h = 40 W/m"°C. (a) obtain an expression or mathematical model that allows calculating heat transfer as a function of the diameter of each fin.(b) Five fins with diameters of 2, 5, 10, 15, and 20 mm are available with a length of 10 cm for all, and only heat transfer is considered. heat by convection which of them have a greater heat transfer? heat flux with the diameter of the pin? (d) what would be the main factor to consider during future analysis if the fins appear…
A thermocouple junction, which may be approximated as a sphere, is to be used for temperature measurement in a gas stream. The convection coefficient between the junction surface and the gas is h=400W/m².K, and the junction thermophysical properties are ĸ= 20W/m.°K, c= 400J/kg.°K and ρ=8500kg/m³. Determine the junction diameter needed for the thermocouple to have a time constant of 1s. If the junction is at 25°C and is placed in a gas stream that is at 200°C, how long will it take for the junction to reach 199°C?
Calculate the over-all coefficient of heat transfer U for a piece of glass1/8-in thick, exposed to still air at 70 °F on one side and 0 °F air moving at15 mph on the other side.
Consider convective cooling of a two-dimensional streamlined strut. Rather than conducting expensive experiments involving pressurized hydrogen, an engineer proposes to take advantage of similarity by performing wind tunnel experiments using air at atmospheric pressure with T∞=23°C. The rate of heat loss per unit object length is ????′ =50 ??.Determine the required air velocity in the wind tunnel experiment VAir and the average convective heat transfer coefficient in the hydrogen ℎ̅H2