Determine the convection coefficient associated with airflow, Mechanical Engineering

Assignment Help:

An experiment to determine the convection coefficient associated with airflow over the surface of a thick stainless steel casting involves insertion of thermocouples in the casting at distances of 10 mm and 20 mm from the surface.  When the experiment was performed in a well insulated air duct so that the temperature of the walls surrounding the steel surface was the same as the air temperature, the thermocouples measured the temperatures of 50°C and 40°C in the steel, respectively, when the air and the surrounding wall temperatures were 200oC.

a)      If the steel has a thermal conductivity of 15 W/m2K and surface emissivity of 0.95, what is the convection coefficient between the steel and hot air?

b)      What are the contributions of the convective and radiation heat fluxes to the steel casting?

In the repeated experiments the duct insulation was removed and even though the hot air temperature was the same as before, i.e., 200oC, the surrounding walls temperature dropped to 20oC. As a result the steady state heat flux to the steel casting dropped by 13.3% compared to the first experiment.

c)      Assuming the same convection coefficient as the value calculated in part a), what would be the temperatures measured by the thermocouples?

d)     Suppose that the steel casting were well insulated from all sides except for the surface from which the distance to thermocouples is measured. Assuming the same convection coefficient as the value calculated in part a), what would be the temperatures of the thermocouples when:

i)                    The experiment is performed in the well insulated duct at T = Tsurr = 200oC?

ii)                  The experiment is performed in non-insulated duct at T = 100oC and Tsurr = 20oC?


Related Discussions:- Determine the convection coefficient associated with airflow

What is transfer molding, Q. What is Transfer molding? Transfer molding...

Q. What is Transfer molding? Transfer molding was developed largely to avoid the disadvantages found which compression molding. • Transfer molding can make intricate or quit

Simple mechanism, differentiate between kinematic chain and mechanisms

differentiate between kinematic chain and mechanisms

Series spot welding, Series Spot Welding In series welding, a portion o...

Series Spot Welding In series welding, a portion of the secondary current by passes any weld nugget being formed. And This shunt current passes through one of the panels being

What are the advantages and disadvantages of induction motor, What are the ...

What are the advantages and disadvantages of induction motors? A coil of 500 turns is linked by a ?ux of 0.4 mWb. If the ?ux is reversed in 0.01 second, ?nd the e.m.f induced i

Basic definitions - air transportation, BASIC DEFINITIONS - Air transportat...

BASIC DEFINITIONS - Air transportation: A civil engineer dealing with airport engineering shall have to know the precise meaning of some terms. These are defined below :

Chemistry, Ask question #Minimum 100 whow to detect the presence of 2nd gro...

Ask question #Minimum 100 whow to detect the presence of 2nd group basic radicals ?ords accepted#

Maximum shear stress and angle of twist, Maximum shear stress and angle of ...

Maximum shear stress and angle of twist: Torques are applied on the shaft as illustrated in Figure. Discover in which portion of the shaft, maximum shear stress & angle of twi

Define application of drilling machine, Application of Drilling machine ...

Application of Drilling machine Drilling machines of dissimilar capacity and configuration are basically used for originating cylindrical holes and occasionally for enlarging t

Determine the response of the system, A force F(t) is suddenly applied to a...

A force F(t) is suddenly applied to a mass m which is supported by a spring with a constant stiffness ‘K'. After a short period of time T, the force is suddenly removed. In the mea

Bicycle frame design, You are required to design the central section of the...

You are required to design the central section of the bicycle frame which consists of the seat tube, top tube, down tube and head tube. You can ignore the seat stays, chain stays a

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd