Influence of Hole-Pressure Error on Pasty Propellant Rheological Test Results

Abstract

Abstract Pasty propellants are viscoelastic fluids that exhibit a normal stress difference in shear flow. This phenomenon causes the pressure data measured by the pressure tap to be inconsistent with the expected value, which is represented by the hole-pressure error. In order to find out its influence on the rheological measurement results, this paper simulate the tube flow with the pressure tap based on PTT model. Results show that the pressure value in the circular section decreases with the increase of radial distance, and there is a weak secondary flow and lateral flow at the entrance of the pressure tap. By analyzing the pressure drop data of tube flow, the power law model is used to fit the desired pressure drop and the measured pressure drop respectively. It indicates that the hole-pressure error results in a small fitting value. However, the discrepancy between the power law model and the material has a certain positive effect. It can reduce the influence of the hole-pressure error on the forward calculation results by selecting the appropriate working range.