Numerical Study of Turbulent Flows over Launch Vehicle Configurations

Bigarella, E. D. V.; Azevedo, João Luiz F.

doi:10.2514/1.6889

Cited by 13 publications

(3 citation statements)

References 17 publications

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“…This analysis tended to confirm the destabilizing effects predicted by the earlier analyses of Ericsson [4]. The use of CFD in the analysis of launch vehicles has expanded over the last several decades [6][7][8][9][10][11][12]. For current and future launch vehicles, it can be expected that CFD will be an integral part of the design from the conceptual stage.…”

Section: Introductionmentioning

confidence: 53%

Computational Aeroelastic Analysis of the Ares Crew Launch Vehicle During Ascent

Bartels

Chwalowski

Massey

et al. 2010

28th AIAA Applied Aerodynamics Conference

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Static and dynamic aeroelastic analyses have been performed for the Ares I crew launch vehicle during atmospheric ascent. It is shown that, through the transonic speed range, there is a rapid change in the static aeroelastic center-of-pressure increment with increasing Mach number. The greatest sensitivity to grid resolution is observed through the transonic range. Dynamic aeroelastic analyses are also performed to assess the aeroelastic stability of the launch vehicle. Flexible dynamic linearized quasi-steady analyses using steady rigid line loads are compared with fully coupled aeroelastic time-marching computational fluid dynamic analyses. There are significant differences between the methods through the transonic Mach number range. The largest difference is at Mach 1. At that Mach number, the linearized quasi-steady method produces strong damping in modes 1 and 2. The unsteady computational aeroelastic method indicates that the first mode is significantly undamped, while mode 2 is strongly damped. The cause of the disparity in damping between modes 1 and 2 is also investigated. A vehicle with no protuberances other than rings produced damping values in modes 1 and 2 that were nearly identical. It is shown that the disparity in damping of modes one and two is due to asymmetric placement of protuberances around the vehicle circumference.

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Section: Introductionmentioning

confidence: 53%

Computational Aeroelastic Analysis of the Ares Crew Launch Vehicle During Ascent

Bartels

Chwalowski

Massey

et al. 2010

28th AIAA Applied Aerodynamics Conference

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“…The Shear Stress Transport (SST) k-ω turbulence model is used to calculate the Reynolds stress of turbulence. The SST k-ω turbulence has been proved to be able to simulate strong turbulent flow problems with adverse pressure gradient in aerodynamics [15][16][17] . In this study, the turbine is assumed to be placed well above the boundary layer above the ground, as a result, uniform velocity is given at the inlet boundary, the continuity of mass and momentum is ensured at the interface between the inner and outer zones of the computational domain.…”

Section: Methodsmentioning

confidence: 99%

Effect of Yaw Angle on Large Scale Three-blade Horizontal Axis Wind Turbines

Zhao¹,

Posenauer²,

Tan³

2022

Hydro. sci. & mar. eng.

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Offshore Horizontal Axis Wind Turbines (HAWT) are used globally as a source of clean and renewable energy. Turbine efficiency can be improved by optimizing the geometry of the turbine blades. Turbines are generally designed in a way that its orientation is adjustable to ensure the wind direction is aligned with the axis of the turbine shaft. The deflection angle from this position is defined as yaw angle of the turbine. Understanding the effects of the yaw angle on the wind turbine performance is important for the turbine safety and performance analysis. In this study, performance of a yawed HAWT is studied by computational fluid dynamics. The wind flow around the turbine is simulated by solving the Reynolds-Averaged Navier-Stokes equations using software ANSYS Fluent. The principal aim of this study is to quantify the yaw angle on the efficiency of the turbine and to check the accuracy of existing empirical formula. A three-bladed 100-m diameter prototype HAWT was analysed through comprehensive Computational Fluid Dynamics (CFD) simulations. The turbine efficiency reaches its maximum value of 33.9% at 0° yaw angle and decreases with the increase of yaw angle. It was proved that the cosine law can estimate the turbine efficiency with a yaw angle with an error less 10% when the yaw angle is between –30° and 30°. The relative error of the cosine law increase at larger yaw angles because of the power is reduced significantly.

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“…While the quasi-steady method of line loads is convenient, very versatile and therefore still frequently used, unsteady aeroelastic CFD launch vehicle analysis has been steadily expanding over the last several decades 9,[11][12][13][14][15][16][17] The use of a nonlinear aeroelastic Reynolds Averaged Navier-Stokes (RANS) solver however is still rare because it is computationally expensive. For this reason there is a move toward incorporating unsteady aerodynamic effects through CFD system identification within a reduced order state space model of the launch vehicle.…”

Section: Introductionmentioning

confidence: 99%

A Quasi-Steady Flexible Launch Vehicle Stability Analysis Using Steady CFD with Unsteady Aerodynamic Enhancement

Bartels

2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Launch vehicles frequently experience a reduced stability margin through the transonic Mach number range. This reduced stability margin is caused by an undamping of the aerodynamics in one of the lower frequency flexible or rigid body modes. Analysis of the behavior of a flexible vehicle is routinely performed with quasi-steady aerodynamic lineloads derived from steady rigid computational fluid dynamics (CFD). However, a quasi-steady aeroelastic stability analysis can be unconservative at the critical Mach numbers where experiment or unsteady computational aeroelastic (CAE) analysis show a reduced or even negative aerodynamic damping. This paper will present a method of enhancing the quasi-steady aeroelastic stability analysis of a launch vehicle with unsteady aerodynamics. The enhanced formulation uses unsteady CFD to compute the response of selected lower frequency modes. The response is contained in a time history of the vehicle lineloads. A proper orthogonal decomposition of the unsteady aerodynamic lineload response is used to reduce the scale of data volume and system identification is used to derive the aerodynamic stiffness, damping and mass matrices. The results of the enhanced quasi-static aeroelastic stability analysis are compared with the damping and frequency computed from unsteady CAE analysis and from a quasi-steady analysis. The results show that incorporating unsteady aerodynamics in this way brings the enhanced quasi-steady aeroelastic stability analysis into close agreement with the unsteady CAE analysis.

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Numerical Study of Turbulent Flows over Launch Vehicle Configurations

Cited by 13 publications

References 17 publications

Computational Aeroelastic Analysis of the Ares Crew Launch Vehicle During Ascent

Computational Aeroelastic Analysis of the Ares Crew Launch Vehicle During Ascent

Effect of Yaw Angle on Large Scale Three-blade Horizontal Axis Wind Turbines

A Quasi-Steady Flexible Launch Vehicle Stability Analysis Using Steady CFD with Unsteady Aerodynamic Enhancement

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