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 HM 152 Potential Flow
 Technical Description

The laminar, two-dimensional flow in HM 152 is a good approximation of the flow of ideal fluids: the potential flow. All physical systems described with the Laplace equation can be demonstrated with potential flow. This includes current and thermal fluxes as well as magnetic flux.
The core element of the HM 152 trainer is a classic Hele-Shaw cell with additional water connections for sources and sinks. The laminar, two-dimensional flow is achieved by water flowing at low velocity in a narrow gap between two parallel glass plates. The parallel flow generated in this way is non-vortical and can be regarded as potential flow. The sources and sinks are generated via eight water connections in the bottom glass plate.  The streamlines are displayed on the glass plate by injecting a contrast medium (ink).
In experiments the flow around bodies is demonstrated by inserting models into the parallel flow. Interchangeable models such as a cylinder, guide vane profile or nozzle contour are included.
To model the flow without models, it is possible to overlay parallel flow, sources, sinks and dipoles as required. This allows the demonstration of the formation of Rankine half-bodies.
The water flow rate and the quantity of contrast medium injected can be adjusted by using valves. The water connections are also activated by valves and can be combined as required.
The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- visualisation of streamlines in
* flow around drag bodies: cylinder, guide vane

profile, square, rectangle
* flow through models: nozzle contour,

discontinuous contraction or expansion
* flow separation, flow with 90° deflection
- modelling the surrounding flow by overlaying

parallel flow and sources and/or sinks
* formation of Rankine half-bodies
* demonstration of a dipole
- analogy between potential flow and other physical

systems which are described by the Laplace

equation

 Features

* Two-dimensional, inviscid potential flow1
* Visualisation of streamlines1
* Modelling the surrounding flow by overlaying

parallel flow, sources and sinks1
* Sources and sinks, individually or in combination

 Alternative products
HM 150.10 -- Visualisation of Streamlines
 Overview
Seepage Flow
 Specification [1] demonstration of potential flow in a Hele-Shaw cell for visualising streamlines[2] flow around models: cylinder, square, rectangle, guide vane profile, various models for changes in cross-section[3] modelling the flow around contours without models by overlaying parallel flow and sources and/or sinks [4] water as flowing medium and ink as contrast medium[5] Hele-Shaw cell made of two glass plates arranged in parallel with narrow gap[6] upper glass plate, hinged for swapping models[7] bottom glass plate with cross-shaped water connections for generating sources/sinks, can be combined as required  [8] grid in the bottom glass panel for optimal observation of the streamlines[9] flow velocity, water supply and water drain in sources/sinks as well as dosage of the contrast medium can be adjusted by using valves Technical Data 2 glass plates: LxW: 910x585mm- distance between the plates: 5mm- bottom glass plate with eight water connections for sources/sinksModels- 6 drag bodies- 2 changes in cross-section- material: rubber- thickness 5mmInjection of the contrast medium (ink)- 19 nozzlesTank for contrast medium: 200mL Dimensions and Weight LxWxH: 1.400x850x1.300mmWeight: approx. 119kg Required for Operation Water connection 300L/h, drain Scope of Delivery 1 trainer1 set of models (drag body, changes in cross-section)Ink, 1L1 set of instructional material Order Details 070.15200  HM 152  Potential Flow
 © 2005 G.U.N.T. Gerätebau GmbH