Investigation on rotor jet interference in a hydraulic reaction turbine for low head low flow water conditions

Abstract

The focus of this paper is to investigate the issue of water jet interference, which is a common flaw in simple reaction turbines. When the turbine’s wall crosses the water jet coming from another nozzle, this is known as jet interference. The governing equations are also used to analyse the Z-Blade simple water reaction turbine for an ideal and practical example, based on the principles of mass-, impulses and energy conservation. Various evaluations of real and potential operating losses for low-head (3–5 m) and low-flow (3 L/s and below) water resources have been conducted. According to experimental data, the Z-Blade turbine Type B achieves the maximum rotational speeds at 450 rpm, followed by Type A at 400 rpm and Type C at 300 rpm. By performing parametric analysis via governing equations, the calculated non-interference speed is approximately twice that of the turbine’s maximum speed. Furthermore, as the turbine reaches its maximum rotational speed at the optimal length diameter, the turbine speed decreases without interference from the jet nozzle rotor. This resembles a phenomenon of non-interference rotor jet on Z-Blade turbine.