Although the information set out here focuses (because of their market leading positions) on the Andersen Cascade Impactor (ACI) and Next Generation Impactor (NGI), all multistage cascade impactors operate on the same principle: size fractionation on the basis of inertial impaction. Instruments such as the ACI and NGI consist of a series of stages each made up of a nozzle plate, with a specific...

Numerical simulations have been performed for assessment of compressibility correction of two-equation turbulence models suitable for large scale separation flows perturbed by pintle strokes. In order to take into account pintle movement, a sliding mesh method was applied. The chamber pressure, mass flow rate, and thrust have been analyzed, and the response lag and sensitivity at the chamber an...

The hypersonic rarefied wind tunnel has lately been developed at JAXA. The characteristics of hypersonic rarefied flows have been investigated experimentally and numerically in this work. Using a sphere pendulous model, the test flow has been probed by measuring its displacement due to the aerodynamic force. In addition, a spatial variation of total pressure of the test flow has also been measu...

Cold spraying is a coating process which enables production of metallic and metallic ceramic coatings with dense (very low porosity level) and pure (low oxygen content) structures. Several coating applications such as corrosion resistance and electrical conductivity rely on these properties. Generally, cold spraying is based on higher particle velocities and lower process temperatures than othe...

An experimental and numerical study of impinging, incompressible, axisymmetric, laminar jets is described, where the jet axis of symmetry is aligned normal to the wall. Particle streak velocimetry (PSV) is used to measure axial velocities along the centerline of the flow field. The jet-nozzle pressure drop is measured simultaneously and determines the Bernoulli velocity. The flow field is simul...

Measurements were made of the flow field structure and the near field parameters of a jet exhausting from a sonic nozzle with a 1.27 cm exit diameter. Compressed air was used for obtaining stagnation pressures up to ~ 5 atmospheres. The jet exhausted vertically from a settling chamber into an acoustically insulated room and through an insulated duct out through the roof. Measurements were made ...

In the present paper a study of the time dependent transonic flow field around a single compressor blade in a Laval nozzle is presented. For the investigation the PIV method has been employed because of its ability to deliver instantaneous flow field information across an illuminated plane with high spatial and temporal resolution. From these instantaneous PIV measurements the mean velocity fie...

NOx emissions in n-heptane/air partially premixed flames (PPFs) in a counter-flow configuration have been investigated. The flame is computed using a detailed mechanism that combines the Held’s mechanism for n-heptane and the Li and Williams’ mechanism for NOx. The combined mechanism contains 54 species and 327 reactions. Based on a detailed analysis, dominant mechanisms responsible for NOx for...

This study evaluates the role of shock wave motion on the instability of the plume exiting an over-expanded, convergent-divergent nozzle. An array of wall pressure transducers was used to track the position of the shock in time, and a Pitot probe was used to obtain simultaneous measurement of the total pressure fluctuations at various points in the jet that emerges from the separation shock. An...

The HYLIFE-II conceptual design proposed using arrays of high-speed oscillating and stationary slab jets, or turbulent liquid sheets, to protect the reactor chamber first walls from damaging neutrons, ions and X-rays. Flow conditioning can be used to reduce turbulent fluctuations in these liquid sheets and thereby reduce surface ripple, or free-surface fluctuations, and delay jet breakup. Sever...