1. Effect of Fins on Heat transfer
Brian Spencer
Steven Besendorfer
Winter 2010

2. Model D T∞ = 23 °C h L Tb Aluminum(k) Aluminum(k) t Ts = 202.25 °C
1/(h*A)
1/(h*At*No) Tb Tb
t/(k*A)
t/(k*A) Ts Ts

3. Purpose/methods Purpose:
Determine rate of heat transfer with and without fins
Determine fin effectiveness
Methods:
Place block on hot plate and measure base and surface temperatures using a thermocouple
Insert fins into block and re-measure the temperatures
Calculate rates of heat transfer and fin effectiveness as shown in the following slides

4. Experimental Procedure
Without Fins
With Fins

5. Calculations

6. Calculations Assumptions: Steady-State
Free convection over a horizontal plate
Sides are well insulated
Effects of radiation are negligible
Ideal contact between fins and base as described in Table 3.1(b)
Properties of pin fins as described in Table 3.5

7. Summary of Results/ Conclusions
q with fins = W
q without fins = 9.34 W
Fin effectiveness = 2.54
We originally wanted to calculate the difference in base temperature with and without fins; however, we learned that fins enhance heat transfer and do not directly influence the base temperature.
Based on this we changed our experiment to find the rates of heat transfer and fin effectiveness.
Our experiment showed that even with a minimal number of small fins the rate of heat transfer can be greatly enhanced; for our experiment, using fins of 1.5” length and 0.5” diameter more than doubled the heat transfer rate.