称重法低温介质流量校验系统方案研究CSCD

液体火箭发动机试验中,流量测量的准确度至关重要。不同于常温流量测量,低温推进剂的流量测量有其特殊性。介绍了称重法低温介质流量校验原理、方法及方案,对流入法排出气体及流出法增压气体流量简略计算公式进行了推导;针对低温容器气枕换热传质特点,对气枕平均温度的一致性进行了讨论。得出了流入法排出气体流量一致性较好、采用流入法可以使低温流量计检定准确度更高的结论。

Analysis of Calibration Precision for Cube-mirror Based on CMM

The cube-mirror is used as process reference for the spacecraft products manufacturing. To analyzing calibration precision for cube-mirror based on CMM, tests with different sampling strategies were done, the repeatability data of the measurement for cube-mirror angle is obtained.Besides, two theoretical analysis methods of analytical and Monte Carlo method are used to calculate the measuring uncertainty for the angle between the adjacent surfaces of the cube-mirror respectively. Data show that, the results of experiment and theoretical analysis are consistent, the measurement uncertainty of the angle between the adjacent surfaces of the cube-mirror obtained by the two theoretical analysis methods is almost the same, the measurement uncertainty of the angle decreases with the increase of the number of sampling points, the minimum value is close to 0.0020°.The method of theoretical analysis can be used to evaluate the calibration precision and planning sampling of cube-mirror for measuring task.