Effects of spontaneous condensation of moist air on the shock wave dynamics around butterfly valves in transonic flows are investigated by experimental and numerical simulations.Two symmetric valve disk shapes namely-...Effects of spontaneous condensation of moist air on the shock wave dynamics around butterfly valves in transonic flows are investigated by experimental and numerical simulations.Two symmetric valve disk shapes namely-a flat rectangular plate and a mid-plane cross-section of a prototype butterfly valve have been studied in the present research.Results showed that in case with spontaneous condensation,the root mean square of pressure oscillation(induced by shock dynamics)is reduced significantly with those without condensation for both shapes of the valves.Moreover,local aerodynamic moments were reduced in case with condensation which is considered to be beneficial in torque requirement in case of on/off applications of valves as flow control devices.However,total pressure loss was increased with spontaneous condensation in both the valves.Furthermore,the disk shape of a prototype butterfly valve showed better aerodynamic performances compared to flat rectangular plate profile in respect of total pressure loss and vortex shedding frequency in the wake region.展开更多
Butterfly check valves are widely used in water supply pipeline systems. Proper design of new valves requires accurate determination of the water impulse force and moment on the disk for transient flow conditions. The...Butterfly check valves are widely used in water supply pipeline systems. Proper design of new valves requires accurate determination of the water impulse force and moment on the disk for transient flow conditions. The impulse moments were measured using pressure measurement and strain gauge measurements. Correlation was developed relating the impulse moment to the velocity and angle that were used to design a new type of valves.展开更多
文摘Effects of spontaneous condensation of moist air on the shock wave dynamics around butterfly valves in transonic flows are investigated by experimental and numerical simulations.Two symmetric valve disk shapes namely-a flat rectangular plate and a mid-plane cross-section of a prototype butterfly valve have been studied in the present research.Results showed that in case with spontaneous condensation,the root mean square of pressure oscillation(induced by shock dynamics)is reduced significantly with those without condensation for both shapes of the valves.Moreover,local aerodynamic moments were reduced in case with condensation which is considered to be beneficial in torque requirement in case of on/off applications of valves as flow control devices.However,total pressure loss was increased with spontaneous condensation in both the valves.Furthermore,the disk shape of a prototype butterfly valve showed better aerodynamic performances compared to flat rectangular plate profile in respect of total pressure loss and vortex shedding frequency in the wake region.
文摘Butterfly check valves are widely used in water supply pipeline systems. Proper design of new valves requires accurate determination of the water impulse force and moment on the disk for transient flow conditions. The impulse moments were measured using pressure measurement and strain gauge measurements. Correlation was developed relating the impulse moment to the velocity and angle that were used to design a new type of valves.
