View Factor Orientation (or View factor or shape factor) plays an important role in radiation heat transfer. View factor is defined as, "fraction of radiation leaving surface 'i' and strike 'j' ". Summation Rule (View Factor) If there is are similar surfaces 'i' and 'j' , then: Blackbody Radiation Exchange Radiation Exchange between Opaque, Diffuse, Gray surfaces in an Enclosure 1. Opaque 2. Surfaces 3. Two surface enclosure Radiation Shield It is used to protect surfaces from radiation act like a reflective surface. References: Material from Class Lectures + Book named Fundamentals of Heat and Mass Transfer by Theodore L. Bergman + My knowledge. Photoshoped pics are developed. Some pics and GIF from Google. Videos from YouTube ( Engineering Sights ).
Material Engineering ↠ The study of the characteristics and uses of different materials such as metals, ceramics, composites, polymers that are employed in science and technology.
Material Science ↠ defines as the relationship between structures and properties.
It is process in which selection of an appropriate material in mechanical design is chosen after simulating under different loading conditions.
Stress Analysis can be done by using Ansys Software.
For mechanical properties of material ↠ click here.
Hardness
Hardness is defined as, "measures the material resistance to the local plastic deformation". The softer the material, the deeper is the indentation and the lower the hardness index number.
Hardness test are performed to find the properties of material because:
Simple and inexpensive.
Test is non-destructive (that means it cannot damage material).
Mechanical properties often are estimated from hardness.
Hardness Testing Technique
Brinell Test ↠ use 10 mm sphere of steel/tungsten carbide.
Reynolds Number: Reynolds Number is the ratio of Inertial forces to the Viscous forces. By knowing this number, one can describe the flow whether the flow is laminar, turbulent or transitional flow. There are three possibilities of the range of Reynolds Number: If Reynolds number < 2100 or 2300 ⟺ Laminar Flow If Reynolds number > 4000 ⟺ Turbulent Flow If 2300 < Reynolds number < 4000 ⟺ Transitional Flow In case of different shapes other than circle, the formula for Reynolds Number remain the same however diameter involves in the formula become Hydraulic Diameter which is given by: For pipe: Critical Reynolds Number ⟾ The Reynolds number at which the flow becomes turbulent Re cr For different shapes, the hydraulic diameters are given by: Completely Filled Flow In Closed Channel: If pipe is is considered to filled completely with closed channel, then following are the conditions which...
Gear Forming by Machining Formation of gear through machining consists of following methods: Form Milling by Disc Cutter Form Milling by End Mill Cutter Shaper, Planner and Slotter Broaching 1. Form Milling by Disc Cutter It is defined as, " Tooth is cut one by one by plunging the rotating cutter into the blank " . Each gear needs a separate cutter. 8 - 10 standard cutters are available for producing 12 - 120 teeth gears. Used for big spur gears of large pitch. 2. Form Milling by End Mill Cutter It includes the cutting of tooth at a time and then indexed for the next tooth space for cutting. For a small volume production of low precision gears. Set of 10 cutters ↠ 12 - 120 teeth gears . Used for teeth of large gears/module. To reduce cost, same cutter is often used for multiple sized gears resulting in profile errors . Characteristics: Use of Hardened stainless steels (HSS) form milling cutters. Use of Ordinary milling machines. Low production rate (need of indexing...
Mechanical Injection System: Used to inject fuel into the combustion chamber. Fuel speed > air speed at delivery point to atomize fuel. Amount of fuel delivered into the air stream going into the engine is controlled by pump which forces the fuel under pressure. A device used to initiate and control the combustion process is called Mechanical Injection System. Functional Requirements of Injection System: Metering of Fuel: Used to control fuel to meet speed and load requirements of the engine. Injection Timing: Have proper injection timing to obtain max. power, fuel economy and proper burning. It is done by Camshaft or Push rod (Rocker Arm) Mechanism . Proper Control of Injection Rate: To get desired heat release pattern during combustion. Proper Atomization of Fuel: Proper making of droplets to make best Air/Fuel mixture. Proper Spray Pattern: Distribution of droplets to ensure rapid mixing of fuel & air. Uniform Distribut...
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