TecQuipment’s Hele-Shaw apparatus produces streamlines in a laminar, steady flow. It allows students to study various source and sink arrangements, and look at flow around an unlimited variety of different shaped models. The apparatus can represent water seepage through solids, and can simulate any process satisfying the Laplace equation in two dimensions. Thus lecturers can also use it to represent flow in other branches of engineering, such as aerodynamics or electricity and heat flow.
The apparatus works with a steady, air-free water supply and suitable drain. The equipment consists of a channel formed between two plates. Water flows along the channel at a low Reynolds number, so the inertia forces are not important.
A dye flowing through several small holes at the upstream end produces streamlines. The removable top glass plate has grid-lines to help analysis of the flow patterns. The apparatus comes with a rubber sheet from which to cut out various shapes of models. When placed between the two plates, students can see the streamline patterns flowing around the models. Also, valves and a vacuum pump allow students to connect two sources and two sinks (or any combination of both).
To perform experiments, students start the water flow and open a dye valve just enough to produce easily visible streamlines. They then use valves to allow water to flow from a source point or drain into a sink point, or various combinations of flow or sink points. The vacuum pump strengthens the sink points.
To incorporate models into the free stream of the apparatus and study the effect on streamlines, students cut the shapes they need from the rubber sheet (supplied). They then sandwich the model between the two plates of the apparatus and start the flow.
To provide a constant head and smooth, air-free flow from your water supply, TecQuipment offers the optional Header Tank (H9a).
Various flow visualisation experiments in two dimensions, including sink and source points and flow around models, for example:
- Sources and sinks in a uniform stream
- Doublet in a uniform stream
- Flow around a cylinder (disc) and an aerofoil
- Flow through an orifice and a diffuser
- Flow through a heat exchanger
- The momentum equation
- Laminar flow relationship for flow between two parallel plates
- Mean velocity equations (including seepage in soils)
- Potential flow relationships