Numerical Investigation On Performance Of Vortex Tube Separator

Compared with fixed-wing aircraft,helicopter does not require a dedicated track,with good flexibility and mobility,and it can carry out various missions such as lifting,transportation,rescue or attack in harsh environment like desert,ice field and atmospheric layer over the sea,where a lot of dust particles,ice particles and corrosive liquid drops.A helicopter gas turbine needs a massive intake of air when it works.Abrasion,scale deposition,particle fusion,corrosion in the gas turbine and blocking in the cooling ducts are extremely easy to happen caused by the intake of a large number of particles in air.Research shows that usually hard particles of diameter of 5 to 10 ?m will wear on the metal surface.In order to ensure reliability and life of gas turbines,the development of air filter with higher separation efficiency and lower flow resistance becomes an important task.By using numerical simulation method,a high-performance axial vortex tube separator was studied in this paper,which is used for helicopter inlet filter.Numerical investigation of two-phase flow of gas and particles in the vortex tube separator was finished.The variation of separation performance of vortex tube separator with particle diameter was studied,with the separation characteristic curve of separator given,and the physical mechanism of the movement of particles in the vortex tube separator was explored.The flow characteristics such as pressure and velocity in the separator were analyzed.The flow loss in vortex tube was summarized and its influencing factors were also analyzed.In order to study the effect of working conditions on the performance of vortex tube separators,the effects of inlet angle and air outlet pressure on the separation performance of different diameter particles were analyzed.Research results show that an appropriate inlet angle can improve separation efficiency of small diameter particles,but it also can depress separation efficiency of larger diameter particles;reducing air outlet pressure can improve separation efficiency of small diameter particles,but it has little effect on larger diameter particles.In order to optimize the separation performance of vortex tube separator,the effects of swirl pitch and axial exit position on separation performance were analyzed.Research results show that by reducing the pitch of swirl vane,separation efficiency increases for small particles and flow resistance also increases at the same time.By increasing the axial distance between ends of swirl vanes and outlets of separator,can also increase separation efficiency.