飞溅和喷雾评价的推荐性操作规程

[中文适用范围]： 本 SAE 推荐做法提供了测量在潮湿路面上行驶的车辆产生的飞溅和喷雾的一般指南。该指南描述了视频数字化和激光分析方法。当喷雾云叠加在黑白棋盘上时，视频数字化方法使用视频图像和黑白棋盘之间的对比度测量作为测量模糊喷雾的方法。激光法采用激光透过喷雾云的透射率作为测量手段。由该实践的用户决定哪种方法最适合他们的需求。这两种方法之间没有隐含的关系，尽管预计测试车辆配置之间相对喷雾减少的排名将大致相同。除非另有说明，本文档中列出的所有部分均被视为这两种方法所共有的部分。 [外文原描述]： This SAE Recommended Practice provides general guidelines for measuring the splash and spray produced by vehicles operating over wet pavements. The guidelines describe both the video digitizing and the laser methods of analysis. The video-digitizing method uses video images and contrast measurements between black and white checkerboards when a spray cloud is superimposed on them as a means of measuring the obscuring spray. The laser method uses laser transmittance through the spray cloud as the means of measurement. It is left to the users of this practice to decide which method is best suited to their needs. There is no implied relationship between these two methods, although it is expected that the ranking of relative spray reduction between test vehicle configurations would be approximately the same. All sections listed in this document are to be considered as common to both methods, unless otherwise noted.There are complex interactions of variables that affect splash and spray, and by its nature, it is a very chaotic, turbulent phenomenon. This document attempts to address these variables as completely as they are understood at this time. Until they are better understood, it is necessary to limit this recommended test procedure to the following conditions:aIt only applies to “A-B” comparisons done under the “same” conditions as outlined in the test procedure.bTests done at different sites may not necessarily be comparable, depending on the exact conditions and specific site locations at the time of the tests.cBecause uncontrollable variables such as wind speed and direction, water depth, humidity, and temperature can have a profound effect on measured results, small differences (on the order of 10 to 15%) in measured splash and spray may not be meaningful and the relevance of such small measured differences should be viewed with caution.dResults from the testing should be reported as the difference between the 95% confidence bands and not as the differences between averages.eEach configuration tested shall have a separate value with 95% confidence bands reported for each of eight wind conditions using the downwind rule, as outlined in the data reduction.This shall ensure that the variability of each wind condition is accounted for with the 95% confidence bands and compared as separate data sets. The results shall in no way be misrepresented as absolute numbers.Cross Reference: ASTME501,ASTME524