A combined blast fence is introduced in this paper to improve the solid blast fences and louvered ones. Experiments of the jet engine exhaust flow (hereinafter jet flow for short) field and tests of three kinds of blast fences in two positions were carried out. The results show that the pressure and temperature at the centre of the jet flow decrease gradually as the flow moves farther away from...

Particle Image Velocimetry (PIV) measurements for six separate flow bypass ratio five nozzle configurations have recently been obtained in the NASA Langley Jet Noise Laboratory. The six configurations include a baseline configuration with round core and fan nozzles, an eight-chevron core nozzle at two different clocking positions, and repeats of these configurations with a pylon included. One r...

The valve mass flux Gv is the calculated value for an ideal (isentropic) nozzle Gn from an appropriate model, multiplied by a discharge coefficient Kd, which accounts for any discrepancies between the (ideal) nozzle model and flow in a real nozzle, as well as any differences between the flow in the nozzle and the actual valve: Gv = Kd Gn (2) As shown in Figure 1, there are obvious similarities ...

S EPARATION of supersonic flow in a convergent–divergent nozzle is a fundamental fluid phenomenon that affects a large variety of applications, from fuel systems to aircraft engine nozzles. When a supersonic nozzle is operated at pressure ratioswell below its design point, a shock forms inside the nozzle andflowdownstreamof the shock separates from the nozzle walls. Even though flow separation ...

for planting fine seeds in cellular trays, an automatic pneumatic seeder was designed, constructed and evaluated. catia software was used to design and analysis the system parts of the seeder. different parts of the seeder, including vibrating seed hopper, vacuum boom, seed picking nozzles, seed tube, pneumatic system and electronic control unit for automation of the seeder, were designed and c...

A conventional, axial‐flow, air‐blast orchard sprayer was used to make applications to the outside row of a semi‐dwarf apple block. Fluorescent tracer was applied at the same rate using either disc‐core nozzle sets or air‐induction nozzles fitted with flat‐fan tips. The experiment included measuring the percent area of spray coverage on leaves after three variations in spray application method....

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 ...

The objective of this paper is to computationally analyse shock waves in the Convergent Divergent (CD) Nozzle. The commercial CFD code Fluent is employed to analyse the compressible flow through the nozzle. The analysis includes static pressure, temperature, Mach number and density of the flow for different nozzle pressure ratios (NPR i.e., the ratio between exit pressure of the nozzle to ambie...

Direct numerical simulation is used to study the effect of crossflow on the dynamics, entrainment and mixing characteristics of vortex rings issuing from a circular nozzle. Three distinct regimes exist, depending on the velocity ratio (ratio of the average nozzle exit velocity to free-stream crossflow velocity) and stroke ratio (ratio of stroke length to nozzle exit diameter). Coherent vortex r...

in this study, an electrostatic sprayer which had been previously designed and constructed was evaluated in order to quantify the charging of droplets. liquid atomization was achieved by using an ultrasonic nozzle. the nozzle maximum flow rate was 25 milliliters per minute and vibration frequency was about 30 khz. the induction method was used for charging the output droplets. all experiments w...