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货物表面与衬垫之间缝隙内的流动行为，从而了解吸力的产生机理。采用涡棒法对轴对称衬垫进行了数值计算。在此基础上，进行了二维实验，以了解物体表面的压力分布情况。主要研究结果如下：(1)涡棒法对这类三维复杂流动具有很强的计算能力。(2)缝隙中形成的环流对吸力的产生起着重要作用。(3)垫片边缘的长度对吸力的产生有重要影响。(4)在环形射流的垫片中，当缝隙变小时，衬垫内部形成缓冲室，从而使排斥力变得更强。(5)当间隙变大时，实验结果表明，当垫片边缘长度较大时，在环形射流外会产生较大的负压区。(6)实验结果表明，条纹边缘的压力几乎为大气压力。(7)随着条纹长度的增加，负压区逐渐增大，直至接近间隙的5倍。(8)当条纹长度大于间隙的5倍时，负压区变得几乎不变。

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.