CAJ | 학술논문

采用颗粒成像测速仪(PIV),实验测定了相同功率下两种不同叶片长度的六直叶涡轮桨(RT桨)的流动场,分析了叶片长度对液相速率、湍流动能和尾涡特性的影响规律,并研究了桨叶离底距离对尾涡特性的影响.结果表明,径向速率分布差别不大,而长桨叶的轴向速率大于短桨叶,最大相差达40%.对于湍流动能,二者在近桨叶区数值相近,但在远桨叶区长叶桨较短叶桨的湍动要强,最大差值30%;对于尾涡特性,上下尾涡发展轨迹、涡量大小是不对称的,下尾涡较上尾涡发展稍快,且涡量较大,涡量大20%左右.
채용과립성상측속의(PIV),실험측정료상동공솔하량충불동협편장도적륙직협와륜장(RT장)적류동장,분석료협편장도대액상속솔、단류동능화미와특성적영향규률,병연구료장협리저거리대미와특성적영향.결과표명,경향속솔분포차별불대,이장장협적축향속솔대우단장협,최대상차체40%.대우단류동능,이자재근장협구수치상근,단재원장협구장협장교단협장적단동요강,최대차치30%;대우미와특성,상하미와발전궤적、와량대소시불대칭적,하미와교상미와발전초쾌,차와량교대,와량대20%좌우.
The flow fields of two Rush ton turbines with different lengths of blades have been measured by using particle image velocimetry (PIV) under the same power input. The effect of the blade length of the Rushton turbine on the velocity, turbulent kinetic energy and trailing vortices was investigated. The effect of clearance between the impeller and tank bottom on the trailing vortices was also studied. The results show that the radial velocities of the two impellers were almost the same under the same power input. The impeller with the longer blades produced up to 40% larger axial velocity than that with shorter blades. The turbulent kinetic energy generated by the impeller with longer blades was larger than that with shorter blades in the region far away from the impeller, with the largest difference being 30 % ; the turbulent kinetic energies were almost the same in the region near the impeller. The pair of vortices was asymmetric, with the lower vortex developing a little faster and generating more vorticity (nearly 20% ) than the upper one.