AERODYNAMICS OF MATERIAL HANDLING OF AIR-CUSHION AND SUCTION TYPE BY CONTROL OF AIR FLOW

本研究的目的是为了弄清物品表面与垫块之间空隙中的流动行为，从而了解吸力的产生机理。采用涡棒法对轴对称垫块进行了数值计算。在此基础上，进行了二维实验，了解了货物表面的压力分布。主要研究结果如下：(1)涡旋棒法对三维复杂流动具有较强的求解能力。(2)间隙内形成的循环流动对吸力的产生起着重要作用。(3)垫边的长度对产生吸力很重要。(4)在采用环形射流的垫块中，在射流内部形成缓冲腔，使排斥力变强，若间隙变小。(5)如果间隙稍大，在垫边长度较大的情况下，环形射流外会产生较大的负压区。(6)实验结果表明，条纹边缘的压力接近大气压力。(7)负压区随着条纹长度的增加而增大，直至接近间隙的5倍。(8)当条纹长度大于间隙的5倍时，负压区基本保持不变。

The purpose of the present research is to make clear the flow behavior in the gap between the surface of goods and the pad in order to know the mechanism of generation of suction force. The numerical calculation of axis-symmetrical pad is carried out by vortex stick method. Further, a two-dimensional experiment is carried out to know the pressure distribution on the surface of goods. The main results obtained in this research are as follows :(1) The vortex stick method is powerful for these three-dimensional complicated flows.(2) The circulatory flow formed in the gap plays an important role to generation of suction force.(3) The length of the fringe of pad is important to generate the suction force.(4) In a pad using an annular jet, the cushion chamber is formed inside the jet, so that the repelling force becomes strong, if the gap becomes small.(5) If the gap becomes a little larger, the large negative pressure zone is generated outside the annular jet in the case where the length of the fringe of pad is large.(6) Experimental results show that the pressure at the edge of fringe is almost atmosphere.(7) The negetive pressure zone becomes large with the increase of the length of the fringe till it becomes lalmost five times of the gap.(8) The negative pressure zone becomes almost constant for the larger length of fringe than the five times of the gap.