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 ).
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Equilibrium of a Rigid Body
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Rigid Bodies:
Bodies which don't deform under load are called Rigid Bodies. It is the only supposition in Statics.
Conditions for Rigid Bodies Equilibrium:
Condition for equilibrium of rigid Bodies are:
If the total force on a rigid body is zero then the body shows translational equilibrium as the linear momentum remains unchanged.
If the total torque on a rigid body is zero then the body showa rotational equilibrium as the angular momentum remains unchanged.
Free Body Diagrams:
While solving a problem in statics, we should draw free Body diagram in order to make problem even more easier.
Reaction of Connection In 2D plane:
Types of connection, reaction and number of unknowns for different connections are given by:
Equations of Equilibrium (2D):
When the body is subjected to a system of forces, which all lie in the x-y plane, then the forces can be resolved into their x abd y components. So, the conditions for equilibrium are:
ΣFx = 0
ΣFy = 0
ΣMo = 0
Two-Force Members:
A two force member is a body that has forces (only forces, no moments) acting on it in only two locations.
Three-Force Members:
A three-force member is a rigid body with no force couple acted upon by three forced at three different locations.
Reactions of Connections in 3D Plane:
Types of connection, reaction and number of unkowns for different connections are given by:
Equations of Equilibrium (3D):
When the body is subjected to a system of forces, which all lie in 3-dimensional plane, then the forces and moments can be resolved into their x, y and z components. So, the conditions for equilibrium are:
Center of Gravity: It is defined as; The resultant weight of a system which passes through a single point is called Center of Gravity ( G ). Center of Mass: It is defined as; The point at which the whole mass of the system acts. The concept of center of mass is cleared from the video given below: Centroid of a Volume: Objects having three dimensions have the centroid which is its geometric centre. Centroid of an Area: Objects having two dimensions have the centroid which is its geometric centre. Centroid of a Line: Objects having linear dimensions have the centroid which is its geometric centre. Composite Bodies: A composite body consists of a series of connected simpler shaped Bodies which may be rectangular, triangular, semicircular, etc. References: www.youtube.com www.wikipedia.com http://web.aeromech.usyd.edu.au/statics/doc/friction/Friction1.htm From Book Engineering Mechanics sta...
Flywheel It is defined as, " a machine element which serves as reservoir which stores energy during the period when energy supply is more than the requirement and releases it when energy is less than requirement " . Used in IC, reciprocating (compressors or pumps) engines, presses, etc. Excess energy is stored in flywheel and release to crankshaft during other strokes in which no energy is developed. If space is small ↠ use small diameter and solid flywheel . If space is not limited (like for presses, crushing machine, hammering machine) ↠ use large diameter and hollow flywheel . Purpose of flywheel is to: reduce amplitude of speed fluctuation (sinusoidal) for constant power output. reduce maximum torque required. energy stored and release when needed during cycle. Parts of flywheel are Rim ↠ outer portion of flywheel (which is like a wheel). Hub ↠ center part which is installed on shaft. Arms or Needle ↠ rods joining rim to ...
Projection: The term Projection is defined as: Presentation of an image or an object on a surface. The principles used to graphically represent 3-D objects and structures on 2-D media and it based on two variables: Line of Sight. Plane of Projection. Line of Sight & Plane of Projection: Line of sight is divided into 2 types: Parallel Projection Converging Projection & A plane of projection is an imaginary flat plane upon which the image created by the lines of sight is projected. Orthographic Projection: When the projectors are parallel to each other and perpendicular to the plane of projection. The lines pf sight of the observer create a view on the screen. The screen is referred to as the Plane of Projection (POP). The lines of sight are called Projection lines or projectors. Rules of Orthographic Projection: Edges that are parallel to a plane of projection appear as lines. Edges that are incl...
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