No description available.

The methodology and analysis used to characterize the performance of a sabot/rod as it is subjected to lateral and axial loading during launch is presented. The methodology described incorporates the experimental and numerical portions of the evaluation. Three separate sabot/rod designs are evaluated for their performance in the launch tube and are compared with one another. The experimental portion of the research involved full-scale testing of two separate sabot/rod designs in a 120-mm launch tube that was slightly bent. When launched through the bent tube, the sabot/rod system was forced to negotiate lateral displacements at axial velocities of approximately 5400 fps. This combination of axial velocity and lateral displacement produced significant lateral loading on the sabot/rod system. A 2.3-MeV x-ray unit was used to determine the lateral displacement that occurred as the sabot/rod was forced through the bent tube. After the sabot/rod exited the launch tube, the sabot separation and rod straightness were recorded by four 150-keV x-ray units. The in-bore radiography experiments used x-ray shielding techniques to reduce x-ray scatter, and layered indexed film and intensifier screens to record the sabot/rod image. The processed film was computer scanned with a microdensitometer and was remapped on the computer to enhance the x-ray image. Results indicated rod lateral displacement accuracy to 0.007 in. Test results were used to benchmark the numerical analyses used to characterize the in-bore performance of each sabot/rod system studied. The numerical portion of the research involved three-dimensional modeling of the sabot/rod systems in three launch-tube environments: a perfectly straight launch tube, an existing accuracy tube, and the slightly bent tube used in the experimental program. Because of the good agreement between the experimental and numerical models, stress, strain, and displacement time histories were obtained from the numerical work and used to evaluate each of the three sabot/rod systems in three launch environments. A dynamic analysis was performed for each of nine separate models. Sliding surfaces, nonlinear constitutive relations, and multiple materials were used for each analysis. Results from both the experimental and numerical analyses are presented.

Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / This thesis describes a study based on propellant injection conditions which was performed with a single shear coaxially injected liquid rocket engine combuster. Steady state operation was closely examined with the thrust chamber operating at sub critical, near critical and supercritical pressure levels with respect to the thermodynamic critical pressure of oxygen. It was found that unstable combustion could not be triggered whatsoever with LOx/H₂ propellants at near or supercritical pressure, irrespective of operating conditions. Such findings illustrate that operating near or above the critical pressure of propellants (oxygen) results in inherently stable combustion process over a broad range of operating conditions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283711 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007

Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / This thesis describes a study based on propellant injection conditions which was performed with a single shear coaxially injected liquid rocket engine combuster. Steady state operation was closely examined with the thrust chamber operating at sub critical, near critical and supercritical pressure levels with respect to the thermodynamic critical pressure of oxygen. It was found that unstable combustion could not be triggered whatsoever with LOx/H₂ propellants at near or supercritical pressure, irrespective of operating conditions. Such findings illustrate that operating near or above the critical pressure of propellants (oxygen) results in inherently stable combustion process over a broad range of operating conditions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283711 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007