Thesis (M. S.)--Aerospace Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Ben Zinn; Committee Member: Eugene Lubarsky; Committee Member: Jerry Seitzman.

Thesis (M.S.)--Ohio University, March, 1999. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, November, 1997. / Title from PDF t.p.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 111-113). Also available via the Internet.

Due to the fact that cross flow fuel injection is widely used in gas turbine engines combustors, it is important to understand the mechanisms that control the spray breakup within the cross flow. In spite of a lot of work done in this field, very few studies have been carried out under conditions typical of aerospace applications. This thesis describes a series of experiments carried out to simulate these conditions in order to characterize the formation of spray within a high speed, high pressure and high temperature cross flow close to conditions typical of aerospace applications. Fuel spray characteristics were studied for Jet-A fuel injected into a crossflow (M=0.2 and M=0.35) of preheated (T=555K) air at a chamber pressure of 4 atm. It was seen that larger droplets could be found in the periphery of the spray while smaller droplets could be found closer to the injection plate. In most cases, the droplet velocities were seen to lag the incoming air flow velocity by 20-40% and a spray hat structure was created by the jet in crossflow near the injection wall most likely caused by vortex flow created around the liquid column (jet). The influence of Weber number was then studied. It was seen that shear breakup mechanism dominates at We greater than about 100. Droplets diameters were found to be in the range of 15-30 microns for higher values of We, while larger droplets (100-200 microns) were observed at Weber number of 33. The initial sharp-edged injector was then replaced by a smooth-edged injector having. Spray characteristics from the two injectors were compared. The spray produced by the smooth countersunk injector penetrated further into the test section away from the injector orifice by approximately 2mm. This injector also produced droplets with a significantly smaller mean diameter (D10). The average droplet velocities in the vertical direction deviated from the incoming air flow velocity to a lesser degree using the countersunk injector. Meanwhile, droplets from this injector had a higher average velocity in the direction of fuel injection between the core of the spray and the orifice wall.

This thesis presents the results of a three-dimensional flow calculation with a model of turbulent viscosity for a tandem-bladed inducer in air. The purpose is to understand the 3D flow development through the two blade rows and to compare the results of the calculation 'with experimental data. A literature review tells the story of the inducer from the flat-plate design to the tandem-bladed configuration and explains its role in cavitation management. The results of a previous 3D-calculation on the first blade row alone are summarized and the MEFP code is briefly described. The generation of a grid for the second blade row is presented in detail. Then, it is shown how this new grid is linked to the previous grid for the first blade row to get an overall calculation grid for the whole inducer. Two 2D blade-to-blade calculations are shown. They give an insight into the flow behavior through the inducer and allow a test of the grid. The results of the 3D-calculation are discussed and presented extensively with the velocity vectors, the static pressure contours and the rotary stagnation pressure contours on blade-to-blade, meridional and iso-8 vie"rs. The three passages of the second blade row appear to behave differently with respect to their position relative to the wake of the first blade row. The experimental data are used for comparison at three measurement planes in terms of pressure and velocity. They show a fairly good agreement. The three-dimensional calculation predicts also very well the work done and the efficiency of the overall inducer. / Master of Science