【摘要】 Preston管是量测壁面剪应力的有效量测仪器.鉴于目前尚未在工业上制造生产,所以本文详细介绍了自制Preston管的工艺及其率定过程,以供推广应用.本文还阐明了Preston管的工作原理以及制作技巧.对外径为2.25,1.60,1.30,0.90和0.60毫米的五支自制Preston管在有机玻璃水管中的率定结果表明,与Preston的实验成果符合良好.从而证明自制的Preston管既可用于气流,也可用于水流中光滑壁面剪应力的量测,方便而且可靠.更多还原

【Abstract】 In this paper the processing details and calibration results of a laborratorymanufactured Preston tube are presented in view of the fact that commerial Preston tubes are still not available. Theoretical consideration and practical technigue have been thoroughly reviewed and observed. Five laboratory-manufactued preston tubes with external diameters, equal to 2.25, 1.60, 1.30, 0.9 and 0.60 mm respectively, were calibrated within a perspex water pipe. The calibration chart is in good agreement with Pate’s experimental results. It is concluded that the laboratory manufactured Preston tube is equally convenient and reliable for the measurement of shear stress on smooth boundary when the tube is in turbulent boundary layer both for air and water flow.更多还原