拉瓦尔喷管喉部区域当量直径液力测量方法

拉瓦尔喷管喉径尺寸要求严格，现有成熟的深孔测量方法无法直接应用于拉瓦尔喷管喉部区域当量直径测量。在分析拉瓦尔喷管喉部区域当量直径液力测量的孔口流动模型基础上，提出了基于芯型测头塞规法的拉瓦尔喷管喉部区域当量直径液力测量方法，分析了芯型测头塞规尺寸与孔口流动模型及其相对灵敏度的关系。优选了短孔模型作为拉瓦尔喷管喉部区域当量直径液力测量的基本模型，确定了当量直径液力测量参数，研制了当量直径液力测量原型装置。在该装置上进行了测量试验，分析了芯型测头塞规直径和测量压差对喉部区域过流流量的影响。最终的重复性试验结果表明，该方法的测量重复性误差为±0.001 8 mm，能够满足拉瓦尔喷管喉部区域当量直径测量需要。

Hydraulic Measurement Method for Equivalent Diameter of Laval Nozzle Throat

The requirements of Laval nozzle size are quite strict, and the existing measurement methods can not be used to measure the equivalent diameter of Laval nozzle throat directly. A hydraulic measurement method for measuring the equivalent diameter of Laval nozzle throat based on the core plug gauge is proposed through the analysis of the orifice flow of the throat’s equivalent diameter measurement model. The relationships among the plug gauge size, orifice flow model and its relative sensitivity are analyzed. On this basis, the short orifice flow model is taken as the model for measuring the equivalent diameter of throat. The measurement parameters are determined, and a measurement prototype device is developed. The repeatability error of the proposed measurement method is ±0.001 8 mm.