Free and Force Convection Apparatus

The Apparatus offers basic experiments for targeted teaching on the topic of free and forced convection on various heating elements.
At the heart of the experimental unit is a vertical air duct into which various heating elements are inserted.
An axial fan is located on top of the air duct.
The fan draws in ambient air and guides it through the air duct.
The air flows past a heating element and absorbs heat.
Four heating elements with different geometries are available to be selected.
In order to investigate free convection, two of the four heating elements can be operated outside of the air duct.
The heating elements are designed in such a way to release heat only at their surface.
The compact design ensures rapid heating and a short time for experiments.
The experimental unit is equipped with temperature sensors at the inlet and outlet of the air duct.
The air velocity is measured to determine the airflow rate.
The microprocessor-based instrumentation is well protected in the housing.
The software consists of a software for system operation and for data acquisition and an educational software is connected to the PC via USB.
Heating power and flow rate are adjusted and displayed via the software.
FEATURES:
Experimental determination of the Nusselt number
Free and forced convection
Investigation of the relationship between flow formation and heat transfer during experiments
Description of transient heating process
Functions of the software: educational software, data acquisition, system operation
Calculation of convective heat transfer at different geometries :
Flat plate
Cylinder
Tube bundle
Calculation of typical characteristic variables of heat transfer :
Nusselt number
Reynolds number
SPECIFICATION:
Air duct :
Flow cross-section: 120x120mm
Height: approx. 0,6m
Heating elements, temperature limitation: 90°C
Tube bundle :
Number of tubes: 23
One tube in variable position is heated
Heating power: 20W
Heat transfer area: 0,001m2
Cylinder with an even temperature at the surface :
Heating power: 20W
Heat transfer area: 0,0112m2
Plate :
Heating power: 40W
Heat transfer area: 2x 0,01m2
Cylinder with heating foil to investigate the local heat transfer :
Heating power: 40W
Heat transfer area: 0,0112m2
Axial fan :
Max. Flow rate: 500m3/h
Max. Pressure difference: approx. 950Pa
Power consumption: 90W
Measuring ranges :
Air velocity: 0…10m/s
Temperature: 4x 0…325°C
Heating power: 0…50W
Required for Operation :
230V, 50Hz, 1 phase
230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase