HEAT TRANSFER COEFFICIENT CALCULATION FOR

Heat transfer coefficient calculation for forced convection refers to the process of determining the efficiency at which heat is transferred from a solid surface to a fluid when the fluid flow is induced or forced over the surface. It involves quantifying the rate of heat transfer and the temperature difference between the solid surface and the fluid.

The heat transfer coefficient (h) represents the ability of the fluid to extract heat from the solid surface. It is a key parameter in determining the overall heat transfer rate in forced convection scenarios. The calculation of the heat transfer coefficient involves considering factors such as fluid properties, flow conditions, surface characteristics, and the geometry of the system.

By evaluating the rate of heat transfer, surface area, and temperature difference, the heat transfer coefficient can be determined using appropriate equations or experimental correlations. This calculation helps in understanding and optimizing heat transfer processes in various engineering applications, such as cooling systems, heat exchangers, and HVAC systems, where forced convection is involved.

Accurate determination of the heat transfer coefficient enables engineers and researchers to design and optimize heat transfer systems, improve energy efficiency, and ensure adequate thermal management in various industries and applications.

1. HEAT TRANSFER COEFFICIENT CALCULATION FOR FORCED CONVECTION NAMDEV HADAPAD

2. When heat flow is achived by mixing of warmer portions with cooler portions of same material is known as convection. TYPES: Free convection : mixing of fluid accomplished by current set up when body of fluid is heated such process known as free convection Forced convection : mixing of fluids may be obtained by usinguse of stirrers or agitator or pumping of fluid for recirculation such processes in heat treansfer is designated as convective heat transfer. What is CONVECTION ?

3. HEAT TRANSFER COEFFICIENT

4. METAL WALL- Dotted lines HH and CC – boundaries of hot fluid and cold fluid Temeperature gradient through the line Metal wall thickness is L 1. HOT FLUID SIDE - Maximum temperature in hot fluid - Temperature at boundary - Temperature at actual interface Curve , , temperature gradient from hot fluid to metal wall - Average temperature on hot fluid side   Metal wall       M         N   L HOT FLUID ( turbulenT ) COLD FLUID (turbulent) Z C H

5. 2. COLD FLUID SIDE - is minimum temperature on cold fluid side - is temperature boundry at cold fluid side - Temprature at actual interface Curve , , is temperature gradient metalwall to cold side - Average temperature on cold fluid side   Metal wall       M         N   L HOT FLUID ( turbulenT ) COLD FLUID (turbulent) Z C H

6. SURFACE \ FILM COEFFICIENT The quantity of heat flowing through unit area of the film for unit drop in temperature. Let us consider : Q watt of heat flowing from hot fluid to cold fluid Area of metal wall on hot side - Area of metal wall on cold side - Average area of metal wall -  

7. Film coefficient on hot side= = So = is known as thermal resistance on hot side Similarly, film coefficient on cold side And is known as thermal resistance on cold side  

8. OVERALL COEFFICIENT is the resistance on hot fluid side is the resistance of metal wall is the resistance on cold fluid side So overall heat transfer may be written as q=  

9. Right side of the equation multiplied by q= Overall heat transfercoefficient =   (1) (2) Compairing both equations (1) and (2) q=  

10. q= So,   Rate of heat transfer Overall heat Transfer coefficient Temp. Drop Area of heating surface

11. FOR TUBULAR WALL Area “A” replaced by diameter “D” So, overall transfer coefficient is –   =   So, Q=  

12. REFRENCES Food Process Engineering and Technology Zeki Berk Professor (Emeritus) Department of Biotechnology and Food Engineering TECHNION Israel Institute of Technology Israel https://youtu.be/v47uTuEGW9Q

13. THANK YOU