58. Optimizing Pelton Turbines for Refurbishment by Numerical Analysis Pande V.K., Harwani L.K., Ramanathan S.M. (Proceedings, Hydro 2003, Vol. I, Croatia, pp. 129–137). Abstract Conventional CFD packages available in the market solve 3-D Navier stokes equation for closed channel flows and for open channel flows and can be applied to evaluate flow parameters in reaction turbines like Francis & Kaplan type turbines. No commercially available computer package can be used directly to evaluate the two species (air & water) mixed flow phenomena encountered in jet/bucket interaction in Pelton turbines. Flow phenomena occurring in a pelton turbine runner is a very complex as it combines two species (air-water) flow interactions coupled with separation of water into droplets of various sizes and their subsequent miscibility & coalescing to form more droplets or streams. There is an element of randomness in this behaviour and a factor of non-commutativeness in modelling this, in terms of hydrodynamic flow equations. This is further complicated by the fact that the amount of refinement of geometrical & flow data, within which, this phenomena can be captured accurately, by means of a mathematical model, requires immense computer resources. Hence an alternative methodology has been worked out, to circumvent these problems. BHEL has developed a system of computer codes which has been used to analyse and improve the performance of Pelton runner bucket profiles. A high performance, efficient replacement runner has been designed, using suite of computer codes. This meets all stipulated customer requirements and provides a cost effective solution to the needs of renovation & refurbishment of Pelton type hydro turbines. Top Keywords CFD, Navier stokes equation, Reaction turbines, Flow, Pelton turbine, Subsequent miscibility, Hydrodynamic flow equations, Geometrical & flow data, Bucket profiles. Top |