Deployment and Flight Test of Inflatable Membrane Aeroshell Using Large Scientific Balloon

42nd AIAA Fluid Dynamics Conference and Exhibit

2012

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Numerical simulations of a plasma flow around a membrane-aeroshell type reentry vehicle with various physical models combination were performed and radio frequency blackout for transceiver antenna embedded at the rear of the vehicle was investigated. The flow field was assumed to be thermochemical nonequilibrium and was described by the Navier-Stokes equations with a multitemperature model and the equation of state. The simulations were performed for several altitudes including the highest heat flux point according to a reentry orbit data. Through these computations, flow-field properties distributions in shock layer and wake region were successfully obtained in detail. In order to evaluate the radio frequency blackout during atmospheric reentry, distribution of electron number density around the inflatable vehicle were clarified and the RF blackout possibility was discussed. In addition, simulations of electromagnetic waves based on the computational results of the plasma flow calculation were performed with a frequency-dependent finite-difference time-domain method. Electromagnetic wave behaviors in an ionized-gas region behind the inflatable vehicle were investigated. It was seen that the number density of electrons was sufficiently small and the electromagnetic waves can propagate with less reflection and attenuation. From these reasons, we found that the RF blackout hardly occurs during atmospheric reentry. NomenclatureB = magnetic flux density vector, T D = effective diffusion coefficient, m 2 /sec D = electric flux density vector, C/m 2 e = electric charge, C E = electric field vector, V/m f = frequency, Hz J = current density vector, A/m 2 H = magnetic field vector, A/m m = mass, kg n = number density, 1/m 3 S = Poynting vector, W/m 2 t = time, sec T = temperature, K ε r = relative permittivity ε 0 = permittivity in free space, N/V 2 µ 0 = permeability in free space, N/A 2 ν c = collision frequency, Hz σ = conductivity, S/m χ = electric susceptibility

Section: Introductionmentioning

confidence: 99%

Radio Frequency Blackout Possibility for an Inflatable Reentry Vehicle

42nd AIAA Fluid Dynamics Conference and Exhibit

2012

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“…Thus far, experimental and numerical research and development on the elemental technologies of a future inflatable vehicle has been performed. Free flight tests using a scientific balloon were performed in 2004 and 2009 [1]. Then, a reentry demonstration flight was successfully conducted out using a sounding rocket on August 8, 2012 [2,3].…”

Section: Introductionmentioning

confidence: 99%

Examination of Radio Frequency Blackout for an Inflatable Vehicle During Atmospheric Reentry

Journal of Spacecraft and Rockets

2014

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Numerical simulations of the plasma flow and electromagnetic wave around a membraneaeroshell type reentry vehicle were performed using various physical model combinations, and the possibility of radio frequency blackout of transceiver antenna embedded at the rear of the vehicle was investigated. The flow field was assumed to be in thermochemical nonequilibrium, and it was described by the Navier-Stokes equations with a multitemperature model and the equation of state. The simulations were performed for several altitudes including the highest heat flux point according to reentry orbit data. Through these computations, the detailed distributions of the flow-field properties in the shock layer and wake region were successfully obtained. To evaluate possibility of the radio frequency blackout during atmospheric reentry, the distribution of the electron number density around the inflatable vehicle was clarified. A frequency-dependent finite-difference time-domain method was used for simulations of electromagnetic waves, and the physical properties were obtained from the computational results of the plasma flow calculation. Electromagnetic wave behaviors in an ionized gas region behind the inflatable vehicle were investigated. It was found that the number density of electrons was sufficiently small and that the electromagnetic waves can propagate with less reflection and no attenuation. These results suggest that radio frequency blackout may not occur during the atmospheric reentry of the inflatable vehicle.

“…This directly contributes to a decrease in the heat flux on the surface of the vehicle. Free flight tests using a scientific balloon were performed in 2004 and 2009 [10,11]. In addition, JAXA's hypersonic wind tunnel coupled with a numerical simulation approach was used to evaluate the aerodynamic heating in front of an inflatable vehicle [12].…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Heating Around Flare-Type Membrane Inflatable Vehicle in Suborbital Reentry Demonstration Flight

Journal of Spacecraft and Rockets

et al. 2015

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A demonstration flight of an advanced reentry vehicle was carried out using a sounding rocket. The vehicle was equipped with a flexible (membrane) aeroshell deployed by an inflatable torus structure. Its most remarkable feature was the low ballistic coefficient that enables reduction in aerodynamic heating and deceleration at a high altitude. During the suborbital reentry, temperatures at several locations on a backside of the flexible aeroshell and inside the capsule were measured by means of embedded thermocouples. The aerodynamic heating behavior of the vehicle was investigated using the measured temperature history, in combination with a numerical prediction in which a flow-field simulation of the heating was conducted. In this flow-field simulation, both laminar flow and turbulent flow were assumed, and the deformation of the flexible aeroshell was considered. A thermal model of the capsule and membrane aeroshell was developed, and the heat flux profiles of the vehicle surface during aerodynamic heating were constructed based on the measured temperatures. The measured temperature data were found to be in reasonable agreement with the predicted data if the flow field near the capsule of the vehicle was assumed to be laminar, with a transition to turbulent flow near the membrane aeroshell.