Radiation Heat Transfer

-
Image
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 ).
Post a Comment

Transient Conduction

-

Lump

It is defined as, "a body which has constant temperature with respect to position".
        • Temp = function(time).

Lump Capacitance

Ques: When to apply lump capacitance method?
Ans: Apply when 
      1. Temperature is the function of time not space.
      2. When Biot Number is near or equal to zero.
The validity of lumped capacitance method is:

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).

Comments

Post a Comment

HI, we wI'll contact you later

Popular posts from this blog

Techniques and instruments used in Hydrographic Survey

-
Image
Hydrographic Survey Hydrography is the science which determines the physical features and the navigable portions of the Earth's surface adjoining coastal areas. Surveyors study bodies of water to see what the floor looks like. Techniques and Instruments used in Hydrographic Survey : Many instruments are used in hydrographic survey like multibeam sonars, LIDAR, multibeam echo sounders(MBES), global positioning system (GPS), laser scanners etc. Among these instruments some are discussed ahead which are mostly used. 1. Light Detection and Ranging: LIDAR is used to measure the elevation or the depths of water bodies by analyzing the reflection of laser light off an object or seafloor.  Bathymetric LIDAR is used to determine is used to determine the depths of water bodies by measuring the time delay between the pulse of transmission and its return signals. 2.Multibeam Sonars: Multibeam echo sounders(MBES) or sonar systems transmit sound energy which strike seafloor a
Read more

Corrections Of Tape

-
Image
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 temperature at which the tape is standardized.       L = the measure length in m. For Foot Unit :                          C t  = 6.45×10^-6  (T m  – 68 )L For Metric Unit :                          C t  = 1.16
Read more

Viscous Flow In Pipes

-
Image
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 are generated to flow liquid. If
Read more