Convective heat transfer refers to the transfer of heat between a surface and a fluid. Convective heat transfer processes are associated with fluid flow movements, i.e. convection. In the case of forced convection, a pump or fan directs the fluid to the transfer surfaces, while in the case of free convection, a flow occurs only due to the difference in density of the heated fluid.
WL 314 and its accessories are used to study convective heat transfer at different geometries of the transfer surface. Typical models such as tube bundles, externally heated tubes and internally heated cylinders are considered. In addition, the chimney effect can be demonstrated under free convection in an air duct.
An air duct with fan serves as the measuring section, in which the model of a heat exchanger is inserted quickly and conveniently with the aid of quick-release fasteners. The air flows past the model, heats up and then exits through an air duct. A streamlined inlet element in the air duct provides a homogeneous flow for conducting the experiment. The volumetric flow rate is set via a throttle valve at the fan outlet. The air duct includes two windows to observe the experiments.
The model of the shell & tube heat exchanger includes two interchangeable tube bundles with different geometries. A heating element, which can be positioned anywhere in the tube bundle, simulates a heated tube. In this way, convective heat transfer can be determined depending on the tube position. Other models are available as accessories.
A Pitot tube and a pressure gauge are used to determine the velocity distribution in front of and behind the models. Heating power and volumetric flow rate can be adjusted. The heating power and the temperatures of air and heater are displayed digitally.