Need a good report for the thermal lab pleaseSolutionOBJECTI

Solution

OBJECTIVE

: The aim of the expriment is

1. to find the effect of forced convection on the heat transfer from a surface at diierent temerature

2. to compare the effect of radiation and covection at different temperature

Definitions

Equipment used in the experiment ( Draw the figure you have given)

The equipent consists basically of a long tube 1meter long and dia 74.15mm with a cooling fan , which forces air into the cylinder.

Procedure:

The notes gives the exact procedure you may copy the same

There is a resistance at the further end of the tube with a thermocouple attached to it to measure the temperature.

The tube has an anemometer to measure the velocity of the air that the cooling fan is pumping in and also a thermocople to measure the remperature of the incoming air.

A thermocople is fixed on the cylinder outr side to measure the temperature of the surface temperature.

Make the table as given with the expt data

V 5 10 15 Qvc= hac A(Ts-Tair), hfc= 1.32[(ts-ta)/d]^0.25

A 0.78 1.52 2.25

Qtot 0.39 15.2 3.375

Air temp 295.2 295.6 298.7

Sur temp 363.7 502.5 639.7

Vs .09 0.1 0.1

hfc 5.74 1.705 1.933

hr 135.6 254 437.8

Qvc 91.2 81,76 152.6 Qvc = h A ( Ts^4-Ta⁴)/(ts-ta)

Qr 3,1x10¹¹ 3.3x10¹² 1.62x10¹³ Qr = hr xA ( Ts^4-Ta⁴)/(Ts-Ta)

Since the second expeiment is not complete no calculation can be carried out.

Now for the first experiment draw the graph as needed and you can infer that the heat desipated increases with the increaase in temperature

Discussion

The heat dissipatd by convection and radiation increases as the temperature of the air increases.

If the forced convection is done it can be shown as more and more is pumped in the heat carried away will increase to some velocity