MECHANICAL RECIPROCATING MOVEMENT CREATION BASED ON REVERSE WATER-HAMMER EFFECT

摘要

Reverse water-hammer, a well known phenomena occurring in hydropower plants due the closures of the guides vanes and fail in pump work in generally considered unwanted in system, because creates steam bubbles(cavitation) are not able to withstand the higher pressure and they condense releases pressure peak of up to some hundred MPa occur.Using water as source of green energy reduces the air pollution problems that cause the global warming.We propose using reverse water-hammer for a mechanical instrument (reciprocating engine) to collect this natural energy.The engine comprises from plunger being push up with sudden close of the water way by it, which was connected with guiding system to reverse it back.The plunger used in the present study is vertical, transparent water tank attached with the mechanism which allows one to easily observe the continuing steady plunger reciprocating motion made by the force of air-water.We are measured the transient pressure peak from our experimental rig. The solutions of unsteady axisymmetric and compressible Navier-Stokes equations and linearized state equation of water are validated with experimental data collected.The compare with theoretical results shows that the numerical validation can be used to predict the maximum pressure peak from reverse water-hammer for laminar flow and would agree with measurement.