Longitudinal dynamic stability of a shuttle vehicle

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76260/1/AIAA-1970-977-416.pd

Angled jet flow model for a diesel engine intake process—random vortex method

A numerical model is developed to study the interactions of multiple angled jet flows in the inlet port plane of the Detroit Diesel 6V-92 two-stroke engine cylinder. The random vortex method is used in two dimensions. Results show axisymmetric swirl initially. As flow develops, the centre of the swirl moves to the mid-radius region and begins to precess about the cylinder centre. The flow becomes progressively more chaotic as time progresses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50198/1/1650030307_ftp.pd

Characterization of particle rebound phenomena in the erosion of turbomachinery

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77337/1/AIAA-44864-924.pd

Numerical experiments on turbulent flow using the random vortex method

Chorin's random vortex method is used to predict the growth of a large-scale coherent vortex structure in the early stages of the development of turbulence in a two-dimensional co-flowing shear layer. The numerical algorithm has been simplified to such an extent that the numerical analysis can be performed on a microcomputer. The numerical solution exhibits the same early turbulent instabilities and vorticity pairings as found in recent flow-visualization experiments. In addition the results are in reasonable agreement with experimental measurements of mean velocity, root mean square fluctuations and Reynolds stresses. One could thus test the shear layer sensitivity to initial conditions and the upsteam boundary conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50096/1/1620240706_ftp.pd

Nonlinear longitudinal dynamics of an orbital lifting vehicle

This paper presents an analytical study of the longitudinal dynamics of a thrusting, lifting, orbital vehicle in a nearly circular orbit. The translational motion is composed of a nonlinear oscillation, or phugoid, and a spiral mode which results in either decay or dilatation of the orbit depending on the perturbed initial conditions. The nonlinear effects on the phugoid period and damping are small in the altitude range considered. Elements of the orbit such as radial distance, velocity, and flight path angle were obtained explicitly as functions of time. The behavior of the variations of these elements is correctly predicted. Explicit expressions for period and damping of the angle-of-attack mode were derived. It is shown that a critical altitude may exist at which the phugoid mode and the angle-of-attack mode have nearly equal periods. Near this resonance altitude linearized solutions are no longer valid and a study of the nonlinear equations shows that there is a strong interactions between the translational and the rotational modes resulting in a switching of the two frequencies of oscillations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42557/1/10569_2005_Article_BF01227791.pd