Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Mechanical Engineering Expert

Problem 1

Provide short answers to the following problems:

a) What the essential condition for a heat transfer process to occur?

b) What is a differentiation between the steady state conditions and the thermal equilibrium state?

c) Is it probable for the steady state temperature profile in a plane wall to be nonlinear at steady state? If yes, provide one ex.

d) Why do you feel cooler throughout a windy day than throughout a calm day even though the air temperature is the same?

e) Why it is more likely to get burn through putting a bare hand in boiling water at 100oC then into hot air at 200oC?

f) What is a temperature gradient in an object sitting in a room in that the temperature is maintained constant after a sufficiently long time?

g) Is it probable that the surface temperature of the object from part f) to be different than the room air temperature? If yes, please elucidate why?

h) What is the chief reason for a ground frost (air temperature is greater than zero)? For a given air temperature, is ground frost more likely to occur at windy or calm conditions?

i) What is a differentiation between and opaque and semitransparent object?

j) What is the chief reason for the surfaces of different objects to be dissimilar when they exposed to sunlight?

k) What is the differentiation between the closed and open systems?

l) What is the inherent differentiation between application of conservation of energy over a time interval and at an instantaneous of time?

m) Why the form of the energy balance for a surface of an object at stable and uneven state conditions is the same?

n) What is the main reason irreversible operation of the actual heat engines?

o) What is the result of the power output of the actual heat engine on its efficiency? Please describe.

Problem 2

An experiment to find out the convection coefficient allocated with airflow over the surface of a thick stainless steel casting includes 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 evaluated the temperatures of 50°C and 40°C in the steel, correspondingly, 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 among 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 although the hot air temperature was the same as before, i.e., 200oC, the surrounding walls temperature dropped to 20oC. As a consequence the steady state heat flux to the steel casting dropped by 13.3% compared to the first experiment.

c) Supposing the same convection coefficient as the value computed in part a), what would be the temperatures evaluated by the thermocouples?

d) Assume that the steel casting was well insulated from all sides except for surface from which the distance to thermocouples is evaluated. Supposing the same convection coefficient as the value computed 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?

Mechanical Engineering, Engineering

  • Category:- Mechanical Engineering
  • Reference No.:- M91070

Have any Question? 


Related Questions in Mechanical Engineering

Write research paper about any topics in manufacturing

Write research paper about any topics in Manufacturing Processes. a. To introduce students to some of the fundamentals of materials (behavior and manufacturing properties) b. To give students a working knowledge of produ ...

Assignmentfor this homework you will be creating scripts in

ASSIGNMENT For this homework you will be creating scripts in SciLab. You will turn in electronically, each of the scripts requested below. This is not a group project, so do your own work. Contact me if you have any ques ...

Now consider a second joint of the same material width and

Now consider a second joint of the same material, width and thickness as the joint in problem 4 above but eccentrically loaded. This time, however, the line of action of the external load is 0.563 in. removed from the ce ...

You have a liquid and its gaseous form in equilibrium in a

You have a liquid and its gaseous form in equilibrium in a piston and cylinder assembly in a constant temperature bath. Give an example of a reversible process.

You need help with a sketch using solid works you only need

You need help with a sketch using solid works. You only need the piston head You don't need the shaft. Attachment:- g172cfinal_project.rar

1 draw the moment diagram for the elbow-biceps-forearm-hand

1. Draw the moment diagram for the elbow-biceps-forearm-hand system and determine the magnitude and location of the maximum moment. 2. How do the magnitudes of the biceps force B and joint reaction J change if the total ...

Part 1- heat1 the is used to express absolute temperatures

Part 1- Heat 1. The _______ is used to express absolute temperatures in the English system of measurement. A. Rankine scale B. Celsius scale C. Kelvin scale D. Fahrenheit scale 2. A silver bar 0.125 meter long is subject ...

Hypochlorite ion used as the chlorinating agent in swimming

Hypochlorite ion, used as the chlorinating agent in swimming pools, can decompose exothermically, in rare occasions even causing ires. he principal decomposition mechanism is believed to be a. Find the steady-state conce ...

Engineering skills project brief flume Engineering Skills Project Brief: Flume Ride

Engineering Skills Project Brief: Flume Ride Introduction Employers are constantly asking for engineering graduates who have good team skills, are problem solvers and are good communicators. On top of that, engineers nee ...

You are asked to design a cylindrical scuba tank with a

You are asked to design a cylindrical scuba tank with a radius R = 16 cm to a pressure of p = 12.0 MPa at a factor of safety of 2.0 with respect to the yield stress. The relevant tabulated yield values for the steel of w ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro