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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Intersection Of Solids
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Intersection Of Solids:
Solids are obtained by the combination of of two or more basic solids. When two or more solids combine, a definite curve/line is seen at their intersection. This curve/line is called curve/line of intersection (COI / LOI) and it is the result of inter-penetration of solids.
Applications Of Intersection Of Solids:
Designing a sheet metal objects.
Automobile Parts.
Moulding patterns.
Forged end of connecting road.
Intersection of two contacting surface, etc.
Inter-Penetration Of Solids:
When one solids penetrates another solids then their surfaces intersect and at the junction of intersection a typical curve is formed, which remains common to both solids. This curve is called Curve of Intersection and it is a result of inter-penetration of solids.
Cases Of Intersection Of Solids:
First we need to discuss the general solution steps of how we draw intersection of solids diagram. So know, we are going to discuss the basic steps:
One solids will be standing on HP and the other will penetrate horizontally.
Draw three views of standing solid, name views as per the illustrations.
Beginning with side view, draw three views of penetrating solids also, mark number of points and name those.
The points which are on the standard generators or edges of standing solids, (in S.V) can be marked on respective generators in F.V and T.V. And other points from S.V should be brought to T.V first and then projecting upward to F.V.
dark and dotted line's decision should be taken by observation side view from it's right side as shown by arrows. Accordingly those should be joined by curvature or straight lines.
Example # 01:
A cylinder 50 mm dia and 70 mm axis is completely penetrated into another of 40 mm dia and 70 mm axis horizontally. Both axes intersect and bisect each other. Draw projections showing curves of intersections.
Example # 02:
A cylinder 50 mm dia and 70 mm axis is completely penetrated square prism of 25 mm sides and 70 mm axis horizontally. Both axes intersect and bisect each other. All faces of prism are equally inclined to HP. Draw projections showing curves of intersections.
Example # 03:
A cone of 70 mm base diameter and 90 mm axis is completely penetrated square prism from top with its axis // to cone's axis 5 mm away from it. A vertical plane containing both axes is parallel to V.P. Take all faces of square prism equally inclined to V.P. Base side of prism is 10 mm and axis is 100 mm long. Draw projections showing curves of intersections.
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...
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...
Introduction Existence of perfect crystals (without defects) are ideal. Instead, we have kinds of imperfection. Ques: Why study imperfections in Solids? When pure metals alloyed (addition of impurities ) like Sterling Silver ↣ 92.5 % Ag and 7.5 % Cu , Cartridge Brass ↣ 70 % Cu and 30 % Zn . These impurities play an important role in semiconductors properties, steel composition, etc. Atomic defects are responsible for reduction gas pollutants emissions in automobiles. Ques: How polluting gases converted into non-pollutant gases? Ans: Molecules of pollutant gases become attached to surface defects of crystalline material. Hence it convert into less-polluting substance. Types of Defects (Imperfections) in Solids There are four types of defects: Point (or Zero-D) Defects Linear (or 1-D) Defects Planar (or 2-D) Defects Bulk (or 3-D) Defects 1. Point Defects It is defined as, " defects associated with one or two atomic position " . Point defects are further divided into tw...
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