Computational analyses of tail fin configurations for a sounding rocket

Missiles and sounding rockets usually deviate from the trajectory due to unstable roll. Fins with cant angles are generally used to provide a rolling moment in sounding rockets and missiles to minimize the instability. Inducing a rolling moment also leads to an increase in the rocket motor’s power consumption due to the rise in drag, so inducing an optimal rolling moment with a minimal increase in drag is a crucial design criterion. It is crucial to maintain the similarity parameters while testing a scaled-down model in a wind tunnel. Therefore, computational fluid dynamics (CFD) is more efficient than extensive wind tunnel tests. In this paper, three-dimensional, incompressible simulations were performed on different models of sounding rockets using commercial CFD package fluent. The simulations were performed with the help of $$k-\epsilon $$ k - ϵ standard turbulence model. The results obtained were tabulated and graphically represented, and the trends of aerodynamic coefficients like $$C_{\text {d}}$$ C d and $$C_{\text {m}}$$ C m were analyzed. The purpose of this study is to analyze the dependency of aerodynamic coefficients on different fin configurations with emphasis on the cant angle. This study will be helpful to researchers designing a sounding rocket and help in maximizing apogee. The experimental and computational results show a favourable comparison. The results will show a particular configuration of fin having greater $$C_{\text {m}}/C_{\text {d}}$$ C m / C d which yields in a greater rolling moment and least amount of drag.

Calibration of the Marshall Grazing Incidence X-Ray Spectrometer Experiment. II. Flight Instrument Calibration

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a sounding rocket experiment that observes the soft X-ray spectrum of the Sun from 6.0–24 Å (0.5–2.0 keV), successfully launched on 2021 July 30. End-to-end alignment of the flight instrument and calibration experiments are carried out using the X-ray and Cryogenic Facility at NASA Marshall Space Flight Center. In this paper, we present the calibration experiments of MaGIXS, which include wavelength calibration, measurement of line spread function, and determination of effective area. Finally, we use the measured instrument response function to predict the expected count rates for MaGIXS flight observation looking at a typical solar active region.