Abstract To understand the micro-vortex structure of Microjet Vortex Generators, a plate with pitched and skewed jet holes was established. Simulations using SST-DDES method based on WENO scheme were conducted to analyse effect pressure, hole interval incoming boundary layer thickness flow structure. The pitch angle skew are 55 degrees 45 respectively. total pressure microjets ranges from 2.5 3...

Of particular importance to the development of models for isolated vortex ring dynamics in a real fluid is knowledge of ambient fluid entrainment by the ring. This time-dependent process dictates changes in the volume of fluid that must share impulse delivered by the vortex ring generator. Therefore fluid entrainment is also of immediate significance to the unsteady forces that arise due to the...

Abstract A computational model is established to investigate the effects of a periodic gust flow on wake structure ventilated supercavities. The effectiveness validated by comparing with available experimental data. Benefited from this numerical model, vertical velocity characteristics in entire field can be easily monitored and analyzed under action generator; further, unsteady evolution param...

Knowledge about the stiffness of fish fins, and whether stiffness is modulated during swimming, is important for understanding the mechanics of a fin's force production. However, the mechanical properties of fins have not been studied during natural swimming, in part because of a lack of instrumentation. To remedy this, a vortex generator was developed that produces traveling vortices of adjust...

In most domestic and commercial refrigeration systems, frost forms on the air-side surface of the air-to-refrigerant heat exchanger. Frost-tolerant designs typically employ a large fin spacing in order to delay the need for a defrost cycle. Unfortunately, this approach does not allow for a very high air-side heat transfer coefficient, and the performance of these heat exchangers is often air-si...

It is shown that if a doubly-infinite vortex sheet has cylindrical shape and strength distributions at some initial time, then this property is retained in its subsequent evolution. It is also shown that in planes normal to the generator of the cylindrical sheet geometry, the nonlinear evolution of the sheet is the same as that of an equivalent strictly two-dimensional sheet motion. These prope...

Generation of well-dispersed, well-characterized fibers is important in toxicology studies. A vortex-tube shaking method is investigated using glass fibers to characterize the generated aerosol. Controlling parameters that were studied included initial batch amounts of glass fibers, preparation of the powder (e.g., preshaking), humidity, and airflow rate. Total fiber number concentrations and a...