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1. PERFORATION EFFECT ON ANNULAR
FIN HEAT SINK
PRESENTED BY
ANISUL ZAFAR [B120220809]
CHHOTU RAM YADAV [B120220817]
PRADEEP KUMAR [B120220834]
RAMAKANT YADAV [B120220839]

2. Problems with the design of solid fins
At 0 degree At 45 degree At 90 degree

3. TYPES OF PERFORATIONS

4. Effect of perforation on thermal
boundary layer
 Perforation enhance the convection current ,resulting in break off thermal
boundary layer thickness between two adjacent surfaces
 Enhance the turbulence in stagnant air particle between two adjacent
surface of annular fin

5. Experimental setup
Test Setup

6. Details of Experimental setup
 Annular fin
 Dimmerstat
 Ammeter
 Temperature indicator
 Thermocouple (K-type)

7. Test Procedure
 Initially a constant power source of 3.2 W is supplied.
 The annular fin cylinder was set at an angular position of 90 degree i.e, air rises parallel to base
cylinder.
 An initial period of 2-3 hrs is required before reaching steady state condition.
 After reaching steady state , temperature of fin surface is measured by thermocouple and ambient
temperature is also measured.
 After taking first reading , increase value of power input and then same steps is repeated as
described above.

8. Result and discussion
Temp. difference for various diameter holes and heat input for D/d=2.33

9. Plot 2
Thermal resistance for various hole diameter and Rab for D/d=2.33

10. Plot 3
Average heat transfer coefficient various hole diameter and temp difference for D/d=2.33

11. Plot 4
Nusselt number for various hole diameters and Rab for D/d=2.33

12. THINGS TO BE CONCLUDED…
 Here we can conclude various relations between thermal as well as
geometrical properties of the heat sink.
 We can compare the heat transfer rate of solid heat sink with perforated
heat sink
 The maximum value of heat transnfer coefficient is found to be for 8 mm
perforation.

13. Applications
 Cooling of electronic component
 Condenser and economizer of thermal power plant
 Dry type cooling tower
 Air cooled compressors
 Cooling of electric motors and transformers

14. Multiple regression technique
LEAST SQUARE METHOD
 Nub=cRab
a D/db
 log(Nub)=log(c) +alog(Rab)+blog(D/d)
 Y=C +aX1+bX2
 𝑌 = 𝑛𝐶 + 𝑎 X1 + 𝑏 𝑋2
 𝑋1𝑌 = 𝐶 𝑋1 + 𝑎 𝑋12 + 𝑏 𝑋1𝑋2
 𝑋2𝑌 = 𝐶 𝑋2 + 𝑎 𝑋1𝑋2 + 𝑏 𝑋22

15. Correlation development
Correlation: Nu=0.00656(Rab)0.8889(D/d)0.2844

16. Validation of Correlation
 Nu=0.00656(Rab)0.8889(D/d)0.2844
 Error in Nusselt number is found to be in the range of ± 10 %

17. Future Scope
 We can use various analysis software's such as CFD to validate the experimental result
by using FVM technique.
 SIMPLE technique.
 TDMA MATRIX.