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Levine, M.

Publications and source records attributed to Levine, M..

At least 19 records

Modeling approach for the Terrestrial Planet Finder coronagraph mission

State of the art modeling for the Terrestrial Planet Finder Coronagraph mission are being developed that will combine thermal, structural, and optical modeling in one package. This tool is discussed as well as specific modeling results highlighting the capabilities of integrated modeling for TPF.

TPF Terrestrial Planet Finder coronagraph

Microdynamic Behavior of a Joint-Dominated Structure On-Orbit

The Interferometry Program Experiments (IPEX) I and II are the first free-flying space experiments specifically designed to characterize the sub-micron dynamic behavior of large flexible structures subjected to on-orbit thermal and mechanical disturbances.

Interferometry

On-Orbit Microdynamic Behavior of a Flexible Structure: IPEX II

The Interferometry Program EXperiments (IPEX) I and II are the first free-flying space experiments specifically designed to characterize the sub-micron microdynamic behavior of large flexible optical structures subjected to on-orbit thermal-mechanical disturbances.

Microdynamic

The art of spacecraft design: A multidisciplinary challenge

Actual design turn-around time has become shorter due to the use of optimization techniques which have been introduced into the design process. It seems that what, how and when to use these optimization techniques may be the key factor for future aircraft engineering operations. Another important aspect of this technique is that complex physical phenomena can be modeled by a simple mathematical equation. The new powerful multilevel methodology reduces time-consuming analysis significantly while maintaining the coupling effects. This simultaneous analysis method stems from the implicit function theorem and system sensitivity derivatives of input variables. Use of the Taylor's series expansion and finite differencing technique for sensitivity derivatives in each discipline makes this approach unique for screening dominant variables from nondominant variables. In this study, the current Computational Fluid Dynamics (CFD) aerodynamic and sensitivity derivative/optimization techniques are applied for a simple cone-type forebody of a high-speed vehicle configuration to understand basic aerodynamic/structure interaction in a hypersonic flight condition.

Abdi, F.

Body conforming grids for general unsteady airfoil motion

A method for computing a new body conforming grid at each time step of an unsteady flow calculation is presented. The method is based on a spring system analogy. It simply updates the grid from the previous time step, hence it requires that an initial grid be created using another method. The method is designed to be independent of the flow equations used, so it can be easily transferred between aerodynamic codes with the same type of initial grid (i.e., O-type). The initial development was done using an O-type grid. It was then extended to C-type grids which required only minor changes to the routine. Results are presented for both O-type and C-type grids. The quality of the updated grids were examined by observing their movement and the flow results they produced. The effect due to the shape of the prescribed grid lines for the O-type grids was examined for a NACA 0012 airfoil undergoing harmonic pitch. The time history of the pressure coefficients of this case was compared with the interpolation scheme and experimental data.

Levine, M.