Effect of Tip Clearance Size on Tubular Turbine Leakage Characteristics

To study the effect of tip clearance on unsteady flow in a tubular turbine, full-channel numerical calculation was carried out based SST k–ω turbulence model using power-plant prototype as research object. Tip leakage characteristics three δ schemes were compared. The results show that value is directly proportional to axial velocity, momentum, and sum but inversely turbulent kinetic energy. At approximately 35–50% direction, velocity energy trough peak variation law, respectively. vortex includes primary (PTLV) secondary (STLV). Increasing increases strength both parts, STLV core overlaps Core A PTLV, B PTLV becomes main part vortex. “right angle effect” causes separation pressure side tip, local low-pressure area subsequently generates gap strengthens vortex, intensifying instability. should therefore be maximally reduced turbines, barring other considerations.