Bench-top apparatus that illustrates free and forced convection from diff erent transfer surfaces.
Key features
• Includes three of the most common heat transfer surfaces: fl at plate, pinned and fi nned
• Thermocouples and a sensitive anemometer measure temperatures and air velocity – shown on a digital display
• Additional hand-held thermocouple probe included – to measure temperatures along the length of the pins and fi ns of two heat transfer surfaces
• Variable-speed fan and variable power heat source for a range of tests
• Can connect to TecQuipment’s Versatile Data Acquisition System (VDAS®)
Learning Outcomes
• Comparing free and forced convection for diff erent surfaces
• Comparison of free convection from vertical and horizontal (fi nned) surfaces
• Comparison of heat transfer surface effi ciency
• Comparing the coeffi cient of heat transfer and Nusselt Number for forced and free convection
• Temperature distribution along fi nned and pinned surfaces
Description
The bench-mounting equipment includes a vertical duct that holds the chosen heat transfer surface and all instruments needed.
TecQuipment includes three diff erent common heat transfer surfaces with the equipment:
• A fl at plate
• A pinned surface – similar to a tubular heat exchanger
• A fi nned surface – similar to the fi ns on air-cooled engines or electrical heat sinks
Each surface has its own built-in variable-power electric heater. Students choose which surface they need to test and fi t it to the duct using simple fixings.
For free convection tests, the heated air rises from the surface and up the duct. For forced convection tests, a variable-speed fan draws air up through the duct and across the surface. Thermocouples measure the air temperature upstream and downstream of the surface and the temperature at the heat transfer surface. The downstream probe moves in a traverse mechanism to measure the temperature distribution across the duct, allowing calculation of the bulk outlet temperature. An additional probe allows students to measure the temperature distribution along the extended surfaces of the pinned and fi nned heater transfer surfaces. A sensitive anemometer measures the air velocity.
Two controls allow students to set diff erent air velocities and heater power for a full range of tests.
A digital display shows the heater power, air velocity and the temperatures measured by the thermocouples.
You can do tests with or without a computer connected. However, for quicker tests with easier recording of results, TecQuipment can supply the optional Versatile Data Acquisition System (VDAS®). This gives accurate real-time data capture, monitoring and display, calculation and charting of all the important readings on a computer (computer not included).
Recommended Ancillaries
• VDAS-B (bench-top version of the Versatile Data Acquisition System)
