 The NASA Lewis Research Center is in a unique position to take advantage of computational fluid dynamics, structural mechanics, and material science to develop new techniques for multi-component, multi-discipline, analysis, design, and optimization of advanced engine systems. To that end, many of the Lewis organizations have formed research teams whose activities are directed towards a common long-range vision of a numerical test cell for studies on advanced engine systems. This unique computational capability in turn sets the stage for new levels of understanding once the scientist or engineer is satisfied that the critical physics are being modeled in the analysis. However, confidence in computational science can only be achieved by detailed comparison with experimental data obtained in test cells or wind tunnels. One such validation experiment was performed in the 10-by-10-foot supersonic wind tunnel at the NASA Lewis Research Center in Cleveland, Ohio. In this experiment, instrumentation was installed in a supersonic inlet designed for Mach 5 to provide detailed data for code validation. A 3D viscous computer simulation of this inlet revealed previously unknown strong secondary flows, as can be seen from these particle traces. These secondary flows are formed because of shockwave interactions with the turbulent sidewall boundary layers, and they create additional inlet losses. The close coupling between analysis and the validation experiment was designed to confirm both the cause and effect of these previously unknown secondary flows. A second important application of computational fluid dynamics is to analyze new concepts in propulsion, such as this supersonic fan blade designed using a 2D analysis. A 3D viscous computer simulation predicted blade pressures shown here in varying colors. The simulation also allowed designers and engineers to visualize secondary flow. Here particle traces show the passage vortex, which can be traced to its origin as a horseshoe vortex ahead of the blade. A third application of computational fluid dynamics at NASA Lewis Research Center lies in the study of interactions which are difficult to measure, such as this supersonic combustor. The combustion process shown was modeled as two hydrogen jets operating at a pressure ratio of 8 and injecting into a rectangular duct. Compression waves are generated upstream of each jet, as can be seen from these color contours. On the top wall, the two jets create an adverse pressure gradient, which causes the free stream particles to move outward laterally, as well as downward. The jets are bent by the free stream. The second jet penetrates more deeply into the free stream flow than the first jet. Deeper jet penetration means enhanced mixing of hydrogen and air, and consequently, more complete combustion. Computational fluid dynamics is also being used to study the interaction of the external environment with a propulsion system. In this example, an under-expanded 3D asymmetric nozzle at a pressure ratio of 10 exhausts supersonically into quiescent air. The nozzle flow expands laterally downstream of the lower lip. Compression waves reflect off the upper and lower shear layers, and a very thin shear layer emanates from the sidewall. The high-temperature high-stress requirements of modern aircraft engines necessitate the development of novel materials, the study of which can greatly benefit from computational material science. Metals, ceramics, polymers, and composites of these are all employed to satisfy the high-temperature strength and durability requirements. Chemical science is concerned with phenomena that range from rapid material processes with solidification rates measured in meters per second in melt spinning to deposition rates of microns per hour in chemical vapor deposition. In chemical vapor deposition, high-temperature coatings, fibers, and semiconductors such as silicon carbide are made. This process involves injecting a nutrient gas into a reactor in which the gas then undergoes several gas-phase chemical reactions as it passes across a heated sceptre. Subsequent surface reactions deposit the needed materials, in this case, silicon, on the sceptre. The computer simulation shown includes the 3D aspects of the reactor. Strong natural buoyancy causes substantial distortions of convecting fields shown here as path lines of neutrally buoyant particles. Subsequent distortions in both the temperature and reacting species fields are evident, resulting in severe non-uniformities in coating thickness and structure. Additional analyses show an excellent agreement between the experimental and numerical deposition rates on the sceptre. This study shows that computational material science can provide information important for the understanding and design of new materials. The NASA Lewis Research Center couples computational and experimental programs for efficiently meeting the requirements of modern aircraft engines. The development and practical application of advanced numerical simulation codes for propulsion systems will require increases in computing power, that is, speed and memory. These advances will have to be matched by improvements in computational support, program development, and computer graphics. The graphics tools are especially important because of the massive amounts of data that need to be understood. The Lewis goal in scientific computing is to provide high-performance graphics workstations having access to parallel processors, mainframe, and supercomputers. NASA Lewis Research Center is moving as rapidly as possible towards the establishment of a high-performance computing environment that will satisfy the long-term experimental and computational needs of future aircraft engine design.