Numerical and Experimental Investigations of Fluidic Thrust Vectoring

Fluidic thrust vectoring (FTV), an ability of air vehicles to manipulate the nozzle flow deflect their longitudinal axis, can satisfy the modern aircraft requirements dramatically. Numerical and experimental studies of FTV are performed with a nozzle pressure ratio (NPR) of 4–10, a secondary pressure ratio (SPR) of 1, 2 or 3, and two different secondary jet locations. Numerical simulations of the nozzle flow are done with solving the Navier-Stokes equations, and the input parameters are set to match the experimental conditions. The thrust pitching moment and the thrust pitching angle are determined to evaluate the FTV performance.特集 : Special Section for the Papers Presented at the Symposium on Mechanical Engineering, Industrial Engineering, and Robotics held at Noboribetsu, Hokkaido, Japan on 11 - 12 January 201

Investigations on Compressible Mixing Layers in Confined Ducts

The lacuna in addressing the fundamentals of compressible mixing layers subjected to pressure gradients in confined ducts motivated the current investigations. Studies are conducted on a canonical compressible mixing layer established between M1=2.0 and M2=1.5 flows within a suction type supersonic wind tunnel. Pressure gradients are imposed on the mixing layer by placing appropriate inserts on the test section walls. High speed schlieren visualizations and static pressure measurements are performed. Interesting shock-shear layer interactions are observed in the test section

Strategy to diagnose ultra-lean (φ < 0.6) premixed flames by acetone-OH simultaneous PLIF with one-laser and one-detector combination

A strategy to diagnose ultra-lean flames utilizing the "acetone-OH simultaneous PLIF" concept via a one-laser and one-detector combination system is presented. The main of the present work is to overcome difficulties encountered in our previous studies; namely, that the seeding amount of acetone used for visualization purposes must be sufficiently small in order to avoid its effect on flame structure (at least <5% of fuel), while clear imaging also must be accomplished under such conditions. For this purpose, several important revisions have been made; 1) the 266 nm excitation line has been added to improve the fluorescence from acetone, 2) a dual-peak band-pass filter has been introduced instead of conventional blue filter and 3) controllability of fine acetone seeding has been improved. The effects of these changes on flame imaging are also investigated. Clear visualization of the flame zone of a very lean premixed flame, of which the limiting equivalence ratio is below 0.6, has been successfully achieved for the first time with one-laser and one-detector system. The time-dependent, near-extinction flame behavior is also clearly imaged, suggesting that this method could utilize to investigate the flame extinction study