# Free & Forced Convection Heat Transfer

Topics: Heat transfer, Heat, Convection Pages: 3 (615 words) Published: December 8, 2012
Sultan Qaboos University
College of Engineering
Department of Mechanical & Industrial Engineering

Heat Transfer
Lab report

Free & Forced Convection Heat Transfer

Mahmood Mohsin AL-Khusaibi85135
Amur Sultan Al-Habsi 86260
Rashid Nasser Al Shabibi85362

Aim:
The objective of this experiment to investigate the use of extended surface to improve heat transfer through surfaces. In addition, another target is to demonstrate the effect of the fluid speed on the heat transfer by convection.

Introduction:
Heat transfer by convection is one of three heat transfer methods which are conduction, radiation and convection. Convection is form of energy transfer between a solid surface and the adjacent fluid. It engrosses the mixed effect of the fluid velocity and conduction. The fluid velocity and the surface area effect are both proportional with the rate of heat transfer.

Theory:
Heat transfer due to convection is expressed by Newton’s law of cooling as:

Qconv = hAs(Ts-Tinf)…………..(1)

Where h is the convection heat transfer coefficient and As is the effected surface area. Heat transfer can be improved by using a larger surface area however, in practice this not always applicable. In similar situation, the surface area can be increased by adding fins or pins. This effect can be demonstrated by comparing different types of extended surface area with a flat plate.

Apparatus:
The apparatus used in this are the duct that work like a wind tunnel different types of plates for heat transfer (flat, pined, finned), heat generator and a stopwatch for time measurement.

Procedure:
First of all, Apparatus for this experiment was prepared. Then, the flat plate heat exchanger was fitted into the duct. Heat power control was set to 75w till the temperature reaches steady state. After that, heat power control was set to 20 w till the temperature reaches steady state once again. Once that happened the temperature was...