Regular in-service inspection is important to verify the integrity of welded nozzle sections in the nuclear industry. Nozzle sections can be susceptible to crack growth due to thermal fatigue and stress corrosion. Early detection of cracks is therefore essential to ensure the continued safe operation of the facilities. In order to reduce the time and cost of such inspections there is a need to ...

The efficiency of two G-vacs (Ryobi RSV 3100 and Flymo BVL 320) was tested to examine the effects of increasing the suction nozzle area and the sampling time whilst keeping total sampling area constant (0.49 m). We tested an a priori hypothesis that increasing nozzle area was significant but that reducing sampling time was not, using a planned comparisons approach. We found that when the nozzle...

Slide gate dithering can reduce nozzle clogging and sticking during continuous casting, but also influences transient flow in the mold and meniscus level fluctuations. In this work, a semi-analytical model was first developed and validated to predict nozzle flow rate from slide-gate opening position. A transient CFD model of 3-D turbulent flow was then validated with surface velocity measuremen...

The supersonic convergent-divergent nozzles have many applications. An advanced design method must be used when the conditions are critical and wave-free stream must be reached. The characteristic method is a general technique in which the design of a nozzle can be achieved. Unfortunately, this technique can be performed only through a lengthy graphical procedure. The aim of this paper is to cr...

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...

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 ...

In this paper some discrete parts of an electrostatic and flat-walled self-aligned valveless, micropump for drug delivery system is designed and simulated. The core component of the system is a piezoelectric diaphragm that can convert the reciprocating movement of a diaphragm actuated by a piezoelectric actuator into a pumping effect. The deflection in the diaphragm was analyzed by applying the...

The main task of the engine 3D CFD simulation is to support combustion design development. New combustion concepts (e.g. Low Temperature Combustion, HCCI, multiple injection strategies ...) can be analyzed and predicted by detailed thermo-dynamical computation. To achieve this aim many simulation tools are needed: each of them should be capable of reproducing the sensitivities of combustion des...