Initial-value ordinary differential equation solution via variable order Adams method (SIVA/DIVA) package is collection of subroutines for solution of nonstiff ordinary differential equations. There are versions for single-precision and double-precision arithmetic. Requires fewer evaluations of derivatives than other variable-order Adams predictor/ corrector methods. Option for direct integration of second-order equations makes integration of trajectory problems significantly more efficient. Written in FORTRAN 77.

Solving Ordinary Differential Equations

저작근 근전도에 관한 정상교합자와 ii급 부정교합자의 비교 연구

A criterion is given for the convergence of numerical solutions of the Navier-Stokes equations in two dimensions under steady conditions. The criterion applies to all cases, of steady viscous flow in two dimensions and shows that if the local ' mesh Reynolds number ', based on the size of the mesh used in the solution, exceeds a certain fixed value, the numerical solution will not converge.

On the Navier-Stokes equations

Review of State of Art of Smart Structures and Integrated Systems

High resolution schemes for hyperbolic conservation laws

The viscous, three-dimensional flowfield of a lifting helicopter rotor in hover is calculated by using an upwind, implicit, finite-difference numerical method for solving the thin layer Navier-Stokes equations. The induced effects of the wake, including the interaction of tip vortices with successive blades, are calculated as part off the overall flowfield solution without using any ad hoc wake models. Comparison of the numerical results for the subsonic and transonic conditions show good agreement with the experimental data and with the previously published Navier-Stokes calculations using a simple wake model. Some comparisons with Euler calculations are also presented, along with some discussions of the grid refinement studies.

Flowfield of a Lifting Rotor in Hover: A Navier-Stokes Simulation

Computational capabilities of a numerical procedure, called TURNS (transonic unsteady rotor Navier-Stokes), to calculate the aerodynamics and acoustics (high-speed impulsive noise) out to several rotor diameters are summarized. The procedure makes it possible to obtain the aerodynamics and acoustics information in one single calculation. The vortical wave and its influence, as well as the acoustics, are captured as part of the overall flowfield solution. The accuracy and suitability of the TURNS method is demonstrated through comparisons with experimental data.

TURNS - A free-wake Euler/Navier-Stokes numerical method for helicopter rotors

The simulation of turbulent compressible flows requires an algorithm with high ac- curacy and spectral resolution to capture different length scales, as well as nonoscillatory behavior across discontinuities like shock waves. Compact schemes have the desired resolution properties and thus, coupled with a nonoscillatory limiter, are ideal candidates for the numerical solution of such flows. A class of compact-reconstruction weighted essentially non-oscillatory CRWENO schemes is presented in this paper where lower order compact stencils are identified at each interface and combined using the WENO weights. This yields a higher order compact scheme for smooth solu- tions with superior resolution and lower truncation errors, compared to the WENO schemes. Across discontinuities, the scheme reduces to a lower order nonoscillatory compact scheme by excluding stencils containing the discontinuity. The schemes are analyzed for scalar conservation laws in terms of accuracy, convergence, and computational expense, and extended to the Euler equations of fluid dynamics. The scalar reconstruction is applied to the conserved and characteristic variables. Nu- merical test cases are presented that show the benefits of these schemes over the traditional WENO schemes.

James D. Baeder

Papers

Flowfield of a Lifting Rotor in Hover: A Navier-Stokes Simulation

TURNS - A free-wake Euler/Navier-Stokes numerical method for helicopter rotors

Compact reconstruction schemes with weighted eno limiting for hyperbolic conservation laws

Indicial Aerodynamics in Compressible Flow-Direct Computational Fluid Dynamic Calculations

Implicit Hole Cutting - A New Approach to Overset Grid Connectivity