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Mechanical Engineering

Mechanical engineering is a disciple of engineering that applies the principles of physics and material science for analysis, design, manufacturing and maintenance of mechanical systems. It involves the production and usage of heat and mechanical power for the design production an operation of machines and tools. Mechanical engineering requires an understanding of core concepts such as mechanics, kinematics, thermodynamics, materials science, structural analysis and electricity. They use these principles to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, weapons, medical devices and many more.

Mechanical engineering as a field of study emerged during the industrial revolution. However, mechanical engineering principles can be traced back to thousands of years ago. This field continually evolves to incorporate advancements in technology, and mechanical engineers today can pursue many different fields such as composites, mechatronics, and nanotechnology.

Mechanical engineering companies in industrialized nations have begun to incorporate computer-aided engineering programs into their design and analysis processes. Solid modeling computer-aided design (CAD) is often used. This method has many benefits, including easier and more extensive visualization of products, and the ability to create virtual assemblies of parts.

Computer-aided engineering programs allow quick and inexpensive iterations of the design process. This allows engineers to develop products that will better meet cost, performance and other constraints. This allows for no physical prototype to be created until the end of the design process. 

Categories within Mechanical Engineering

Aerospace Engineering

Postings: 9

Aerospace engineering is the discipline concerned with the research, design, development, construction, testing, science and technology of aircraft's.

Acoustical Engineering

Postings: 4

Acoustical engineering is the branch of engineering dealing with sound and vibration.

Manufacturing Engineering

Postings: 72

Manufacturing engineering is the discipline that deals with different manufacturing practices and the research and development of systems, processes, machines, tools and equipment.

Ideal solutions concerning rotating solid and hollow shafts

3a. A solid shaft of diameter 30mm rotating at 1000rpm delivers a power of 25kW determine (assume Shear Modulus for the shaft, G=80 GPa) The Shear Stress in the shaft The angular twist of the shaft as a result of the Shear Stress from part (i) The important parameters to note here are Power, P=25kW=25,000W

What is the power needed to accelerate a flywheel?

Please see the attached file for full problem description. I need to calculate torque for this question: A gearbox and flywheel are as shown in FIGURE 4 (attached). The output shaft rotates in the opposite direction to the input shaft at 5 times its speed. The gearbox has an efiiciency of 92%. If the flywheel is sol

Heat Transfer Problem: Transient Solutions

See the attached file. Molybdenum is utilized in high temperature situations because of it high melting point. It is silvery white in color, very hard, and has one of the highest melting points of all pure elements. Molybdenum on Earth is not found free but as a compound. The only pure Molybdenum that has ever been found was

Balancing masses on a shaft supported by two bearings

1. A shaft 2m long 1500 rev min-1 between the bearing shown in figure below. Bearing have forces 5kN and 3kN acting in same plane as shown. A single mass is to be used to balance the shaft so that reactions are zero. The mass is to be placed at a radius of 200mm from the shaft centre 180° from the direction of bearing reaction

A simple torque question

A 1000 lb uniform platform is rotated by a green shaft (centered) as shown. The ends of the green shaft are each connected to a motor - one on either side of the platform. If the platform starts out from rest in horizontal position, how much torque is need to rotate this platform 180 degrees in 3 seconds (assume gravity is prese

Heat Loss Calculations for a Spherical Martian Surface

See attached for the question with the accompanying diagram. A spherical habitat is built under the Martian surface. There is power generation in the habitat. This causes the surface to be at a uniform temperature of 30˚C. The Martian surface is at a uniform temperature of 10˚C. Calculate the heat loss. Assume the habitat

Electrolysis - Aluminium extraction

a. Aluminium is extracted from its ore by an electrolytic process. One extraction plant uses an applied e.m.f. of 5 V, and a current of 225 000 A. One tonne of aluminium is extracted after 14 hours. i. What is the power consumption of the electrolysis? ii. What is the effective electrical resistance of the cell? iii. How mu

Stress-strain and fracture toughness

(a) Sketch the typical stress-strain curve for a metal and a ceramic. Using the sketch, indicate the following properties; elastic and plastic regions, yield points, Ultimate Tensile Strength (UTS), strain energy and fracture toughness. (b) A cylindrical specimen of a titanium alloy with a Young's modulus of 107 GPa has an ori

Thurst Specific Fuel consumption of a Turbofan engine

The question : A turbofan engine on a test stand in the maintenance shop is being run at a continuous setting of 22,700 lbs of thrust. The TSFC is 0.5 lbs/lb-h. A fuel reservoir of 1000 gallons of JET A is feeding the engine. How long can it run at this power setting in minutes? A gallon of JET A weighs approximately 6.7 lbs.

Estimating fractions of a cost

Estimate what fraction of the price of a pocket calculator is required to cover the cost of developing the product. Based on producing half a million calculators per year.

Maximum load P

Please see the attached file. Three plates are joined with a 12 mm diameter pin as shown. Determine the maximum load P that can be transmitted by the joint if: a) The maximum normal stress on a cross-section of the plates at the pin must not exceed 400 MPa. b) The maximum bearing stress between a plate and the pin must not

Pressure Study - System Interaction

Phase 1 Initially ALL Valves A, B, C, D, E and F are closed. ALL Tanks A, B, C, D, E are separated and each sealed from the atmosphere. Tank E initially has 3' of air @ 40 psi Tank C and Tank B initially contain air @ 32.476 psi Pipe K is 12" id; initial air pressure is 32.476 psi Phase 2 Valve D is opened 1st Valve F

Pressure Studies 1.6 Tank A B C&D

Please see full description in attached document. Phase 1 Initially Valves A, B, and E are closed. Tank A and B are separated and each sealed from the atmosphere. Tank A initially has 3' of air @ 40 psi Tank C and Tank B initially contain air @ 32.476 psi Pipe K is 12" id; initial air pressure is 32.476 psi Phase 2 V

Static Engineering System for Stress & Bending Moments

This question involves maximum bending moment calculation, maximum stress calculation, graph sketches of tensile & compressive stress dimensions for cross sections that minimize stress with given values and % reduction of maximum stress with new calculated cross sections. See attachment for problem.

static engineering systems for stress and bending moments

As per attachement. includes; maximum bending moment maximum stress in a beam graph sketches for tensil and compressive stresses dimensions for cross section that minimise stress with given values percentage reduction of the maximum stresswith new calculated cross section

Simple Harmonic Motion Frequency

A body moving with Simple Harmonic Motion with a frequency of 3Hz has a maximum velocity of 2.5m/s. Find its velocity. Please see attached file for further details regarding problem. Question - Simple Harmonic Motion A body moving with Simple Harmonic Motion with a frequency of 3Hz has a maximum velocity of 2.5m/s. Find it

Flat Belt Engineering Question

**Please see the attached file for the diagram ** You are to design a Flat pulley drive for a refrigeration system with the compressor pulley diameter being 450mm and the motor pulley diameter being 200mm. The two shafts will be 1.95m apart and connected to a closed belt. Find a. The angle of contact /angle of lap for the tw

Calculation of percentage heat reduction

Water at 90 C flows through a 50mm bore steel pipe of wall thickness 8 mm. Ambient temperature is 18 C. Calculate the heat loss per metre length of pipe. Assuming that the surface heat transfer coefficients remain the same when a layer of hair felt 25mm thick is wrapped around the outside of the pipe, calculate the percentage

A Diesel cycle

The cycle consists of the following stages; 1) 2 air is compressed adiabatically. 2) 3 heat is added at constant pressure. 3) 4 air is expanded adiabatically. 4) 1 air is cooled at constant volume. An engine operating on a Diesel cycle takes in air at state 1 at 1 bar and 12oC. The maximum cycle temperature is at state 3

Derive eulers equation

1- Derive. From first principles eulers equation from the rate of change of momentum 2- Show by integration how Eulers equation derives Bernoullis equation 3- Explain the use of Eulers equation as applied to compressible fluids. Many thanks for any help

Car Deceleration Problem

A car is travelling at a steady speed of 90 km/h when an emergency occurs. The driver carries out a panic-braking stop, locking all the wheels (no ABS!). a. Derive expressions for the deceleration under the following conditions: i. if the car is ascending a slope of angle Q from the horizontal ii. if it is on a horiz

Aeroplane Dynamics for Maximum Take-Off

The maximum take-off mass of an Airbus A380 passenger jet is about 600 000 kg. The lift is provided by the wings, which have a total area of 845 m2. Calculate the following: A) The approximate take-off velocity of the jet when the lift coefficient of its wings reaches 2.1, stating any assumptions you make in your calculati

Cantilever Beam with Maximum Tensile Strength

A cantilever beam is to be made using a symmetrical I section beam. The cantilever is to carry a load of 40kN at a distance 2.5m from the fixed end. The situation allows for a depth of I-beam to be no greater than 250mm. I-beams of this depth are normally supplied with a flange of thickness 8mm and web thickness of 6mm. Calculat

Cylinder problem strains

Determine the strains in thick walled cylindrical vessel with inside diameter 1000 mm and outside diameter of 1400 mm. The vessel is subjected to a pressure of 35 MPa, and an axial stress of 100 MPa (E = 207 Gpa, and mu=0.3)

Determine the stress in a stay at a given temperature

A steel 'stay' of effective length 5m is fitted in between the walls of a ships refrigerated compartment when the temperature is 18 degrees centigrade. Assume zero stress in the stay on completion of fitting. when the temperature falls to -10 degrees centigrade, the gap between the walls is reduced by 0.5mm. Determine the str

Bow Shock Wave Parameters

Please see the attached file for better formula representation. A three-dimensional bow shock wave is generated by the Shuttle Orbiter during atmospheric re-entry. However, there is a region where the shock wave is essentially normal tot he freestream flow. The velocity of the shuttle is 7.62 km/s at an altitude of 75.0 km. T

Saturated R-134a in a chamber P-V Diagram

Saturated R-134a in a chamber undergoes a constant temperature process starting at 52 F and a quality of x-0.15, and ending at a pressure of 44 Ibf/in^2. A) What is the change in specific volume? (20 pts) B) Sketch this process on a p-v diagram. (5 pts)

Shearing stress in glued splice

Determine the shearing stress in the glued splice, when the splice angle is 30 degrees instead of 60degrees. P = 1400lbs. See attachment for diagram.

Determine mass flow rate

Water enters a 2 meter diameter pipe at a temperature of 23 deg C. The water leaves the pipe at a temperature of 97 deg C The laminar flow rate is such that the Reynolds number is 800. What is the mass flow rate? a) Less than or equal to 0.5 kg/sec. b) Equal to or greater than 0.2 m/sec. c) Greater than 0.5 kg/sec