Aerodynamic loads measurement of a sounding rocket vehicle tested in wind tunnel

Abstract

In wind tunnels, aerospace vehicle models are tested in order to analyze their performance in real flight situations. The forces and moments exerted by the airflow on the surface of the test article are measured using multi-component balances. The balance measures the aerodynamic loads by using strain-gages. It is calibrated prior to the tests, resulting in the estimation of the parameters of the polynomial mathematical modelling relating the strain-gage readings to the aerodynamic loads. This paper presents the aerodynamic load values acting on a sounding rocket vehicle under test in a transonic aerodynamic facility. The force and moment coefficients and corresponding uncertainties are also estimated. The vehicle was tested in low Mach number conditions, with the airflow being supplied by the injection system. The second stage of the model was fitted with three different fin deflections. The measured quantities are total pressure, static pressure and total temperature of the flow, as well as the strain gage readings supplied by an internal balance. An analysis of the contribution for the uncertainties in the aerodynamic loads revealed that the measurement precision is the dominant component. The intermediate measurement precision of the tests was also considered.