Conference Paper

MarcoPolo-R ERC Dynamic Stability Characterization : Computational Campaign

Authors:
  • CFS Engineering
  • ESA, European Space Agency
Conference Paper

MarcoPolo-R ERC Dynamic Stability Characterization : Computational Campaign

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Abstract

The objective of the computational campaign within the framework of the MarcoPolo-R Earth Re-Entry Capsule Dynamic Stability Characterization project, is to apply high-fidelity Computational Fluid Dynamics (CFD) methods to determine the dynamic derivatives of the Earth Re-entry Capsule (ERC) in the subsonic-transonic flow regime. In a first step, the selected computational approach has been validated against subsonic free flight tests performed in the VMK experimental facility (vertical wind tunnel) at DLR. A major outcome of these studies is that the flow conditions used in the CFD simulations need to reproduce accurately the experimental setup in order to correctly describe the dynamic stability behavior of the capsule observed experimentally. The second step of the CFD activities has been to perform dedicated computations for extrapolation-to-flight conditions, and then for flight predictions of selected subsonic conditions in order to populate the aerodynamic database (AEDB) in the trajectory portion that is not covered by the ground tests (0.5<M<0.9).

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... ESA's MarcoPolo-R TRP study was supported by a free-flight test campaign dedicated to determination of the dynamic behaviour of the aero shape at the open range facility of ISL (Dobre and Berner 2015). Furthermore, a transient computational simulation campaign was conducted by CFSE for the evaluation of dynamic derivatives of the aero shape in the subsonic regime (Charbonnier et al. 2015). Although the outcome of the whole study was promising, the Marco-Polo-R mission was not selected as an ESA mission due to financial aspects (Barucci et al. 2012;Michel et al. 2014). ...
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Static force and moment measurements are performed on the MarcoPolo-R aero shape in the trisonic wind tunnel TMK. The static stability behaviour of the capsule is characterized in the Mach number range 0.5≤M≤3.5\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.5\le M\le 3.5$$\end{document} reproducing the Mach and Reynolds conditions of the flight trajectory in the supersonic regime. An aerodynamic database is built based on the experimental results. The flow structure around the capsule is visualised in supersonic tests by means of schlieren imaging. Under certain conditions, development of a complex shock system on the leeward side of the inclined capsule is observed. Oil film technique is used to visualise boundary layer phenomena in connection to this shock system. Numerical simulations with the DLR TAU code are performed to support the interpretation of the flow phenomena under these conditions. Graphical abstract Schlieren imaging visualisation of density gradients in supersonic flow. Depending on the test conditions and angle of incidence, a complex shock system is observed on the leeward side of the inclined capsule. Analysis of the shock structure and its impact on aerodynamic coefficients is one subject of the present investigation.
... have been applied on re-entry vehicles in the last few years. The first method "mean value" was mainly applied during the dynamic stability analysis for the MarcoPolo-R capsule [13] and the SpaceRider lifting-body vehicle, while the second method "AoA dependency" was implemented and applied for the Mars Penetrator Entry Descent and Landing (EDL) system analysis. ...
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A Computational Fluid Dynamics analysis of the dynamics of probe and cap-sule shapes at supersonic flight conditions is performed using an automated, inviscid Cartesian-mesh scheme. This analysis uses static and dynamic free-oscillation simula-tions to develop static and dynamic aerodynamic coefficients for three configurations: the Viking, Genesis, and Mars Exploration Rover capsules. These computed coeffi-cients are compared against data reduced from ballistic-range free-flight testing. A comparison of data reduction methods for capsule shapes from computational simula-tions and range data is included. Free-flight simulations agree well with available flight data for both fully-coupled simulations and aerodynamic database fly-throughs based on the developed aerodynamic coefficients. A sensitivity analysis of the aerodynamic coefficients for trajectory simulations at constant altitude is included.
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Viscous, free-oscillation simulations with the Overrow solver are used to predict the aerodynamic behavior of non-liiing capsule shapes in the supersonic speed regime. Computations using hybrid Reynolds-averaged Navier-Stokes turbulence models are examined for two novel atmospheric-entry capsule con an idealized in decelerator concept, and the Orion Crew Module. simulation results are validated against nonlinear aerodynamic models determined from free--ight ballistic-range data analysis. For the Orion Crew Module, two separate methods of reducing identical range data, along with common models tested in separate range facilities, are included. compu-tations demonstrate the efficiency and accuracy of dynamic simulations for developing a nonlinear aerodynamic performance database. Analysis indicates that the typical nonlinear, bluff-body behav-ior is characterized by a rate-dependent dynamic response, which is not currently accounted for in common aerodynamic models.
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The paper gives a broad perspective of the progress made during the last 10 years in solving the Navier–Stokes equations and traces how this simulation technique went from being a specialized research topic to a practical engineering tool that design engineers use on a routine basis.The scope is limited to Navier–Stokes solvers applied to industrial design of airframes with attention focused particularly on developments in Europe. An overview of the different Navier–Stokes codes used in Europe is given, and on-going developments are outlined.The current state of progress is illustrated by computed steady and unsteady solutions to industrial problems, ranging from airfoil characteristics, flow around an isolated wing, to full aircraft configurations.A discussion on the future industrial design environment is given, and developments in Europe towards a more integrated design approach with underlying concepts like ‘concurrent engineering (CE)’ and the ‘virtual product (VP)’ are summarized. The paper concludes with a discussion on future challenging applications.
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The accuracy of tip vortex flow prediction in the near-field region is investigated numerically by attempting to quantify the shortcomings of the turbulence models and the flow solver. In particular, some turbulence models can produce a ‘numerical diffusion’ that artificially smears the vortex core. Low-order finite differencing techniques of the convective and pressure terms of the Navier–Stokes equations and inadequate grid density and distribution can also produce the same adverse effect. The flow over a wing and the near-wake with the wind tunnel walls included was simulated using 2.5 million grid points. Two subset problems, one using a steady, three-dimensional analytical vortex, and the other, a vortex obtained from experiment and propagated downstream, were also devised in order to make the study of vortex preservation more tractable. The method of artificial compressibility is used to solve the steady, three-dimensional, incompressible Navier–Stokes equations. Two one-equation turbulence models (Baldwin–Barth and Spalart–Allmaras turbulence models), have been used with the production term modified to account for the stabilizing effect of the nearly solid body rotation in the vortex core. Finally, a comparison between the computed results and experiment is presented. Published in 1999 by John Wiley & Sons, Ltd.
MarcoPolo-R ERC Dynamic stability Characterization. Technical Note 2.1 -ERC shape Trade-Off and Selection
  • E Clopeau
Clopeau E., MarcoPolo-R ERC Dynamic stability Characterization. Technical Note 2.1 -ERC shape Trade-Off and Selection, February 2014.