The mass balance for a control volume can be defined as any change of mass within the control volume is equal to the net gain of mass flowing into the volume through the control surface. Based on this definition, derive the equation of mass balance for 3 dimensional, steady and incompressible fluid flow.?
In: Mechanical Engineering
Identify the correct statement in the context of forced convection. (Check all that apply.)
A) Natural convection enhances forced convection heat transfer in transverse flow.
B) Natural convection hurts forced convection heat transfer in transverse flow.
C) Natural convection enhances forced convection heat transfer in opposing flow.
D) Natural convection hurts forced convection heat transfer in opposing flow.
In: Mechanical Engineering
A thin-walled cylinder gets 200 kN axial compressive force and 3 kNm torque moment simultaneously. The diameter of the cylinder is 300 mm and the cylinder wall thickness is 3 mm. Determine the main stress that occurs in the cylinder wall element and the maximum shear stress. Ignore the possibility of buckling in the cylinder
In: Mechanical Engineering
Describe the use of Destructive and Non-Destructive Analyses and Containment and Surveillance in the context of safeguards. Compare the different approaches and describe the benefits and shortcomings of each.
In: Mechanical Engineering
Q7 : A cascade refrigeration system is designed to supply 10 tonnes of refrigeration at an evaporator temperature of -40°C and a condenser temperature of 36°C. The load at -40°C is absorbed by a unit using R-22 as the refrigerant and is rejected to a cascade condenser at -10°C. The cascade condenser is cooled by a unit using R-12 as the refrigerant and operating between - 20°C evaporating temperature and 36°C condenser temperature. The refrigerant leaving the R-22 condenser is subcooled by 6°C but there is no subcooling of R-12 refrigerant. The gas leaving both the evaporators is dry and saturated and the compressions are isentropic. Neglecting losses. calculate the COP of whole system
In: Mechanical Engineering
Consider a centrifugal water pump whose geometry and flow conditions are as follows: Impeller outlet radius – 2.5 cm, impeller inlet radius – 1.8 cm, impeller outlet width – 1 cm, design speed – 1800 rpm, Design flow rate120 liters/min, Backward-curved vanes (outlet blade angles) – 60 deg. Assuming 100% efficiency, find: a) the total head, b) absolute and relative discharge velocities, c) theoretical power required at design flow rate and d) the theoretical pump curve
In: Mechanical Engineering
A gas refrigeration cycle with a pressure ratio of 4.3 uses helium as the working fluid. The temperature of the helium is 26°C at the compressor inlet and 50°C at the turbine inlet. Assuming isentropic efficiencies of 87 percent for both the turbine and the compressor, determine (a) the minimum temperature in the cycle, (b) the coefficient of performance, and (c) the mass flow rate of the helium for a refrigeration rate of 20 kW.
ans a)198.76 b)0.574 c)0.0564.
Can you show me the solution step by step please?
In: Mechanical Engineering
A piston-cylinder device, whose piston is resting on a set of stops, initially contains 2 kg of air at 300 kPa and 27ºC. The mass of the piston is such that a pressure of 600 kPa is required to move it upward. Heat is now transferred to the air until its volume doubles.
a) Determine the work done by the air and b) the total heat transferred to the air during this process. c) Also, sketch the process on a P-v diagram
In: Mechanical Engineering
Your objective for this project is to do an Internet-based literature search and describe in detail, the methods/processes used by GE to design and develop green products, sustainable production processes, and implement its eco-friendly supply chain.
In 1500 -2500 words, your report should address the following topics:
3a. Describe the general guidelines for designing an environmentally friendly product;
3b. Product design system/methodology used at GE;
3c. provide some examples of GE’s successful green product designs.
4a. Describe the guidelines used by GE to make their operations/production processes eco-friendly;
4b. Give examples of some of the successful green manufacturing processes used at GE.
5a. Suppliers
5b. Transportation & Distribution
6a. Discuss how successful GE has been in achieving its environmental sustainability goals. Provide some supporting statistics.
6b. Describe some of the challenges GE is facing in implementing its sustainability programs in some of the developing countries.
This is a team/group project. The group size is limited to a maximum of three (3) students. Your report should be 1500 – 2500 words (excluding quoted and bibliographic material) long, typewritten, and professional looking. It should be in the APA format and should be written by you in your own words. The “Turnitin” Similarity Index (SI) of your report should be less than 15%.
In: Mechanical Engineering
Q1: What are the criteria by which machinability is commonly assessed in a production machining operation? Explain the difference between roughing and finishing operations in machining. What is the difference between peripheral milling and face milling? What is the difference between internal broaching and external broaching?
Note: Please write in your own words don't copy and paste.
In: Mechanical Engineering
A venturimeter is placed in a pipe which is at 30 degrees to the horizontal. The pipe carries gasoline of specific gravity 0.8. The diameter at inlet and throat diameter are 5cm and 3cm respectively. A mercury manometer reads a level difference of 10cm.Calculate the flow rate.
In: Mechanical Engineering
Example 3.7: A commercial steel piping system is delivering water at 30°C from pressurized tank A to pressurised tank B as shown in figure below. The internal diameter of the pipe is 2.25 cm. The piping system has a well rounded inlet, 1/4 open gate valve, four 90° flanged bend, two 90° miter bend (with vane) and a sharp exit. The total pipe length is 300 m. Gauge pressure at tank A is 500 bar. If the elevation difference, h is 100 m and water is delivered at 250litre/min. Determined minor losses and gauge pressure at tank B
In: Mechanical Engineering
1. Use Laplace transforms to solve the following differential equations for ?(?) for ? ≥ 0. Use ?(0) = 0 and ?̇(0) = 1 for each case.
i. 0 = ?̈(?) + 2?̇(?) + 4?(?)
ii. 0 = ?̈(?) + 3?̇(?) + 2?(?)
iii. 5 = ?̈(?) + 5?̇(?) + 6?(?)
3. For the three differential equations from problem one determine the steady-state value of the system using:
a. lim?→0 ??(?),
b. lim ?→∞ ?(?) analytically,
c. lim ?→∞ ?(?) using MATLAB
Please solve #3 and show MATLAB code
In: Mechanical Engineering
In: Mechanical Engineering
Q1/ Answer the following:
1. What is the main advantage of direct acting thermostats?
2. What is the purpose of using a capacitor in a two-phase reversible induction motor?
3. What does the controller circuit consist of?
4. what is the pressure equalizing connection and when it is used?
5. What does the damper loss coefficient depend upon?
Q2/ Answer the following:
1. What should the damper motor power overcome?
2. What is the function of the starting relay?
3. What are two techniques used for defrost purposes in automatic defrost refrigerator.
4. How is the cooling plate heater connected?
5. What is the function of the super switch in the domestic deep freezer?
In: Mechanical Engineering