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 ).
Get link
Facebook
X
Pinterest
Email
Other Apps
Equilibrium of a Rigid Body
Get link
Facebook
X
Pinterest
Email
Other Apps
-
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:
TAPING CORRECTIONS There are two types of corrections depending upon the type of errors in tape due to the different conditions. 1. Systematic Errors : Slope Erroneous tape length Temperature Tension Sag 2. Random Errors : Slope Alignment Marking & Plumbing Temperature Tension & Sag 1. Temperature Correction It is necessary to apply this correction, since the length of a tape is increased as its temperature is raised, and consequently, the measured distance is too small. It is given by the formula, C t = 𝛼 (T m – T o )L Where, C t = the correction for temperature, in m. 𝛼 = the coefficient of thermal expansion. T m = the mean temperature during measurement. T o = the tempe...
Diffusion It is defined as, " The transportation of one atom from one state into other state " . Used for hardening of surfaces like die parts, gear, bolt, machine element. Hardening can be done using Temperature-Heat treatment ( diffusion couple ). There are two types of diffusion: Inter-diffusion ↔ in which atoms tend to migrate from region of high concentration to low concentration . Self-diffusion ↔ in which atoms migrate within a solid. Diffusion Mechanism There can be two conditions of moving atoms Empty spaces between adjacent sites. Atoms have sufficient energy to break bond with neighbors atoms which cause lattice distortion during displacement. If we rise temperature, small fractions of atoms is capable of diffusive motion (which cause lattice distortion). Types of Diffusion 1. Vacancy Diffusion It is defined as, " interchange of an atom from a normal lattice position to the adjacent vacant lattice site " . Extent of vacancy diffusion is a function...
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...
Comments
Post a Comment
HI, we wI'll contact you later