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H-11 Centre of Pressure with CAL Software |
This apparatus enables the moment due to the total fluid thrust on a wholly, or partially, submerged plane surface to be directly measured and compared with theoretical analysis. The plane area may be tilted relative to the vertical so that the general case may be studied.
The water is contained in a clear perspex quadrant, the cylindrical sides of which have their central axes coincidental with the axis about which the turning moments are measured. The total fluid pressures on these curved surfaces therefore exert no moment about this pivot, the only moment being due to the fluid pressure on the plane test surface. This moment is simply measured by weights suspended from a level arm.
The head of water is directly measured against a scale on the apparatus and may be read to approximately 0.5mm.
With ordinary care the equipment is capable of veryifying the theoretical analysis to within 1% accuracy.
1. Determination of the centre of pressure of a vertically plane area at various depths of immersion.
2. Determination of the centre of pressure of the general case of a plane area at various angles and depths of immersion.
All results can be compared with theoretical predictions given in the manual.
As part of a continuous programme of computerisation, many of the hydraulics experiments are supplied complete with a dedicated TQ Computer Aided Learning Program consisting of a computer disk and a software manual. Each program provides both Tutorial (text) and Analytical (tables/graphs) sections thus leading the student clearly through the experiment and allowing data to be entered as the experiment proceeds. This test data can be saved on disk for later analysis or printed for inclusion in laboratory reports. Automatic manipulation, reduction and printing of test data in this way offers considerable reduction in laboratory time for both students and lecturers.
This free-standing unit should be levelled with its screwed adjusting feet using the spirit level.
Initially, and after setting the quadrant in the chosen angular position, a preliminary balance must be made using the empty weight hanger and the trimming tank.
Subsequent results are taken by balancing incremental weights placed on the hanger with known quantities of water. It will be convenient to add the water from a small lipped beaker.
The free surface of the water itself provides a way of avoiding parallax errors, by sighting from its underside against the scale.
As the experiment proceeds, the values of the weights and 'h' (the free surface of water below the horizontal balance line) should be plotted and any points which deviate from the general trend checked.
1. A laboratory manual describing the apparatus, operation, theory, experimental procedure and giving typical test results is provided.
2. "A First Course in Hydraulics" textbook by Professor E. Markland is provided.
3. CAL H11 Computer Aided Learning
Quadrant:
inner radius:100mm
outer radius:200mm
breadth: 75mm
marked: 0o & 30o.
Fixed scale:
Calibrated from the horizontal axis 200mm downwards and 40mm upwards in intervals of 2mm.
Balance arm:
radius- 200mm.
H10 is supplied with Computer Aided Learning Software (for any IBM PC or compatible with colour monitor) including disk and manual.
A weight hanger and assorted weights are supplied as standard.
Due to the careful choice of materials and rust resisting finishes, the apparatus is fully protected against corrosion.
None required.
Suitable storage space should be made available when the apparatus is not in use. Cupboard storage is preferred.
Nett: 440 x 150 x 330mm; 5.9kg.
Gross: 0.05m3; 12.5kg. (approx - packed for export)