Review of unsteady aerodynamics of supersonic parachutes

Numerical Study on Aerodynamic Performance of Mars Parachute Models with Geometric Porosities

“…Parachute-like two-body configurations are widely used for decelerating the spacecraft into the atmospheres during the deep space exploration missions [1]. During the Mars exploration mission, a supersonic parachute is always employed to undertake dual tasks: slowing the falling speed and providing stability for the Mars rover [2].…”

“…During the Mars exploration mission, a supersonic parachute is always employed to undertake dual tasks: slowing the falling speed and providing stability for the Mars rover [2]. To date, only the disk-gapband (DGB) parachute has been used successfully to provide good aerodynamic performances in the Martian atmosphere [1]. Maynard firstly conducted the supersonic wind tunnel tests to explore the supersonic aerodynamic performance of parachutes [3] and found that the drag coefficient of the parachute mainly depends on the canopy porosity, Mach number, capsule size, and distance between the capsule and canopy [3,4].…”

“…Maynard firstly conducted the supersonic wind tunnel tests to explore the supersonic aerodynamic performance of parachutes [3] and found that the drag coefficient of the parachute mainly depends on the canopy porosity, Mach number, capsule size, and distance between the capsule and canopy [3,4]. In the recent Mars Science Laboratory mission, it was further found that in supersonic environments, the shock formed ahead of the canopy interacts with the wake from the capsule; these highly unsteady flow fields cause severe drag coefficient fluctu-ation and structure instability [1], which mainly depends on the Mach number, Reynolds number, angle of attack, canopy-tocapsule size and proximity, and material properties of the canopy and cables [1,[5][6][7][8].…”

“…However, among the dependent parameters of the aerodynamic interactions around a supersonic parachutelike two-body system, canopy porosity has not always been fully considered [1], especially in numerical simulations solving supersonic parachute problems. Canopy porosity consists of two main components: the fabric permeability and the geometric porosity.…”

“…However, in NASA's Low-Density Supersonic Decelerator (LDSD) program tests, the supersonic ringsail (SSRS) parachute and supersonic disksail (SSDS) parachute with lower fabric permeability and higher geometric porosity failed to inflate normally. On the contrary, the disk-gap-band parachute with higher fabric permeability and lower geometric porosity (similar total porosity with SSRS or SSDS) succeeded in the Advanced Supersonic Parachute Inflation Research Experiments (ASPIRE) project [1]. The failure of the SSRS or SSDS parachute may be closely related to its complicated geometric porous structures such as gaps and seams.…”