Basic Terms of Mechanical Engineering

List of Basic Terms for Mechanical Engineering :

1. Torque or Turning Force
2. Couple
3. Moment
4. Stress
5. Strain
6. Spring
7. Specific Weight
8. Specific Volume
9. Specific Gravity

10. Specific Heat
11. Viscosity
12. Buoyancy
13. Device for Fluid
14. Draft Tube
15. Thermodynamics Law-
         zeroth law
         First law
         second law
16. Boiler/Steam Generator
17. Super heater
18. Air Pre heater
19. Nozzle
20. Scavenging
21. Supercharging
22. Turbocharging
23. Governor
24. Flywheel
25. Heat Transfer
26. Thermal Conductivity
28. Heat Exchanger
29. Refrigeration
30. 1 tonne Refrigeration
31. Humidification
32. Gear Train
33. Heat Treatment
34. Allowance
35. Tolerance
36. Clearance
37. Stiffness
38. Toughness
39. Fatigue
40. Nuclear Fission
41. Nuclear Fusion
42. Welding
43. Cutting Tool 
45. Indexing
44. Jig
45. Fixture

Details 

Torque or Turning Force:
It is the total amount of force which is required to create acceleration on moving substance.

Couple:
Two forces those acts on equally,p & oppositely on two separate points of same material.

Moment:
It is the amount of moving effect which is gained for action of turning force.

Stress:
It is the force that can prevent equal & opposite force. That means, it is the preventing force. If one force acts on outside of a material, then a reactive force automatically acts to protest that force. The amount of reactive force per unit area is called stress. e.g. Tensile Stress, Compression Stress, Thermal Stress.

Strain:
If a force acts on a substance, then in that case if the substance would deform. Then the amount of deformation per unit length of that substance is called strain.

Spring:
It is one type of device which is being distorted under certain amount of load & also can also go to its original face after the removal of that load.

Its function:

To store energy.

To absorb energy.

To control motion of two elements.

Stiffness:
Load per unit deflection. The amount of load required to resist the deflection.

Specific Weight:
Weight per unit volume of the fluid.

Specific Volume:
Volume per unit mass of the fluid.

Specific Gravity:
It is the ratio of specific weight of required substance to specific weight of pure water at 4 degree centigrade temperature.

Specific heat:
The amount of heat required to increase 1 unit temperature of 1 unit mass.

Viscosity:

Dynamic Viscosity:
The amount of resistance of one layer of fluid over other layer of fluid.

Kinematic Viscosity:
It is the ratio of dynamic viscosity to density.

Buoyancy:
When a body is immersed in a liquid, it is lifted up by a force equal to weight of liquid displaced by the body. The tendency of liquid to lift up an immersed body is buoyancy. The upward thrust of liquid to lift up the body is called buoyancy force.

Devices for fluid:

Hydraulic Machine:
Turbine,Pump,Compressor etc.

Draft tube:
It attaches with reaction turbine . Its function is to reduce energy loss from reaction turbine & it also reduce pressure at outlet which is must blow the atmospheric pressure.

Thermodynamics Law:

Zeroth Law:
If two body are in thermal equilibrium with a third body then these two body are also in thermal equilibrium with each other.

First Law of Thermodynamics:
In a closed system, work deliver to the surrounding is directly proportional to the heat taken from the surrounding.And also, In a closed system, work done on a system is directly proportional to the heat deliver to the surrounding.

Second Law of Thermodynamics:
It is impossible to make a system or an engine which can change 100 percent input energy to 100 percent output.

Calorific Value of fuel:
It us the total amount of heat obtained from burning 1 kg solid or liquid fuel.

Boiler/Steam Generator:
It is a closed vessel which is made of steel. Its function is to transfer heat to water to generate steam.

Super heater:
It is a part of boiler. Its function is to increase temperature of steam into boiler.

Air-Pre heater:
It is a part of boiler. Its function is to preheats the air to be supplied to furnace and it recover heat from exhaust gas.

Boiler 
It is an important term for boiler. It is the difference of pressure above and below the fire grate. This pressure difference have to maintain very carefully inside the boiler. It actually maintained the rate of steam generation. This depends on rate of fuel burning. Inside the boiler rate of fuel burning is maintained with rate of entry fresh air. If proper amount of fresh air never entered into the boiler, then proper amount of fuel inside the boiler never be burnt. So, proper fresh air enters into the boiler only by maintaining boiler 

Nozzle:
Nozzle is a duct of varying cross-sectional area. Actually, it is a passage of varying cross-sectional area. It converts steam's heat energy into mechanical energy. It is one type of pipe or tube that carrying liquid or gas.

Scavenging:
It is the process of removing burnt gas from combustion chamber of engine cylinder.

Supercharging:
Actually, power output of engine depends on what amount of air enter into the engine through intake manifold. Amount of entry aiy if increased, then must be engine speed will increased. Amount of air will be increased by increasing inlet air density. The process of increasing inlet air density is supercharging. The device which is used for supercharging is called supercharger.Supercharger driven by a belt from engine crankshaft. It is installed in intake system.

Turbocharging:
Turbocharging is similar to the supercharging. But in that case turbocharger is installed in exhaust system whereas supercharger is installed in intake system. Turbocharger is driven by force of exhaust gas. Generally, turbocharger is used for 2-stroke engine by utilizing exhaust energy of the engine, it recovers energy otherwise which would go waste.

Governor:
Its function id to regulate mean speed of engine when there are variation in the load. If load increases on the engine, then engine's speed must decrease. In that case supply of working fluid have to increase. In the other way, if load decrease on the engine, then engine' speed must increase. In that case supply of working fluid have to decrease.Governor automatically, controls the supply of working fluid to the engine with varying load condition.

Flywheel:
It is the one of the main parts of the I.C. engine. Its main function id to store energy in the time of working stroke or expansion stroke. And, it releases energy to the crankshaft in the time of suction stroke, compression stroke & exhaust stroke. Because, engine has only one power producing stroke.

Heat Transfer:
It is a science which deals with energy transfer between material bodies as a result of temperature difference.There are three way to heat transfer such as-Conduction Convection Radiation

Heat Exchanger:
It is one type of device which can transfer heat from one fluid to another fluid.

 Example : Radiator, inter cooler, pre heater, condenser, boiler etc.

Refrigeration
 It is the process of removing heat from a substance. Actually, extraction of heat from a body whose temperature is already below the temperature of its surroundings.

Humidification:

It is the addition of moisture to the air without change dry bulb temperature.

Gear Train:
Meshing of two or more gear. It can transmit power from one shaft to another shaft.

Heat Treatment:
Operation involving heating and cooling of a metal in solid state for obtaining desirable condition without being changed chemical composition.Its object-increase hardness of metal.increase quality of metal ( heat, corrosion,wear resistance quality )improve machine

Allowance:
It is the difference between basic dimension of mating parts. That means, minimum clearance between mating parts that can be allowed.

Tolerance:
It is the difference between upper limit of dimension. It is also the permissible variation above and below the basic size. That means maximum permissible variation in dimensions.

Clearance:
It is the difference in size between mating parts. That means, in that case the outside dimension of the shaft is less than internal dimension of the hole.

Stiffness:
It is the ability to resist deformation.

Toughness:
It is the property to resist fracture.

Fatigue:
When a material is subjected to repeated stress below yield point stress, such type of failure is fatigue failure.

Nuclear Fission:
It is a nuclear reaction by which one big nuclear divided into two or more nuclear

Nuclear Fussion:
It is also a nuclear reaction by which one big nuclear will produced by adding two small nuclear.

Welding:
It is the process of joining two similar or dissimilar metal by fusion.

Arc Welding -

* need D.C current

* produced (6000-7000) Degree Centigrade Temperature

Gas Welding -

* Oxygen - acetylene flame join metals

* Oxygen & acetylene gas works

* produced 3200 Degree Centigrade Temperature

Cutting Tool:

Tool Materials for Cutting Tool:
1. High Carbon Steel

2. High Speed Steel (W+Cr+V)

3. Carbide (W Carbide+Ti Carbide+Co Carbide)

Indexing:

It is the method of dividing periphery of job into equal number of division. Actually, it is the process of dividing circular or other shape of work piece into equal space, division or angle.

Jig:
It is one type of device which hold & locate work piece and also guide & control cutting tool. It uses in drilling, reaming and tapping.

Fixture:
It is one type of device which hold and locate work piece. It uses in milling, grinding, planning & turning.