The compressible jet plume emerging from a planar convergent–divergent nozzle containing a separation shock is investigated experimentally and numerically. The investigation encompasses exit-to-throat area ratios (Ae=At) from 1.0 to 1.8 and nozzle pressure ratios from 1.2 to 1.8. Experiments were conducted in a variable-geometry nozzle facility, and computations solved the Reynolds-averaged Nav...

In this study, the flame dynamics of swirl stabilized lean premixed combustion is investigated for kerosene and natural gas operation. A burner retrofitted with a twin-fluid nozzle to allow performing all experiments identical hardware. The mixture preparation complexity stepwise increased from perfectly technically lastly combustion. Flame transfer functions (FTFs) three configurations are pre...

This paper describes Nano-particle based Planar Laser Scattering (NPLS) flow visualization of angled supersonic jets into a supersonic cross flow based on the HYpersonic Low TEmperature (HYLTE) nozzle which was widely used in DF chemical laser. In order to investigate the non-reacting flowfield in the HYLTE nozzle, a testing section with windows was designed and manufactured. The impact of seco...

In this paper, we present our efforts to test experimentally and numerically the concept of bubble augmented jet propulsion. The numerical model is based on a two-way coupling between an Eulerian description of the flow field and a Lagrangian tracking of bubbles using the Surface Averaged Pressure (SAP) model. The numerical results compares favorably with nozzle experiments. A half 3-D nozzle f...

Ultraprecise optical elements are applied in advanced optical apparatus. Elastic emission machining (EEM) is one of the ultraprecision machining methods used to fabricate shapes with 0.1-nm accuracy. In this study, we proposed and experimentally tested the control of the shape of a stationary spot profile by introducing a focusing-flow state between the nozzle outlet and the workpiece surface i...

Spray cooling of a hot surface was investigated to ascertain the effect o f nozzle-tosurface distance on critical heat flux ( CHF). Full cone sprays of Fluorinert FC-72 and FC-87 were used to cool a 12.7 X 12. 7 mm 2 surface. A theoretical model was constructed that accurately predicts the spray's volumetric flux (liquid volume per unit area per unit time) distribution across the heater surface...

This paper presents the design, development and characterization of contractile water jet thruster (CWJT) for mini underwater robot. Instead of electric motor, this CWJT utilizes the Ionic Polymer Metal Composite (IPMC) as the actuator to generate the water jet. The main focus of this paper is to analyze the conceptual design of the proposed CWJT which would determine the thrust force value, je...

The space-time conservation element and solution element (CE/SE) method is used to solve the conservation law form of the compressible axisymmetric Navier-Stokes equations. The equations are time marched to predict the unsteady flow and the near-field screech tone noise issuing from an underexpanded circular jet. The CE/SE method uses an unstructured grid based data structure. The unstructured ...

A high-speed gas flow, generated by a miniature supersonic nozzle for microparticle acceleration, is investigated. In medical application, the powder formulation of drugs can be delivered into human skin or mucosal tissue for the treatment of a range of diseases. One of the main concerns for designing and evaluating such system is ensuing that microparticles are delivered into human skin with a...