The intention of the present study is the detailed analysis of the unsteady vortex dynamics downstream the human glottis during phonation at typical fundamental frequencies of about 120 Hz (for men). A hydraulic respiratory mock circuit has been built-up including a three-times up-scaled realistic dynamic model of the vocal folds. Time-resolving flow measurements were carried out downstream the...

Detailed field measurements and simulations of three-dimensional flow structure were used to develop a conceptual model to explain the sustainability of self-formed pool-riffle sequences in gravel-bed rivers. The analysis was conducted at the Red River Wildlife Management Area in Idaho, USA, and enabled characterization of the flow structure through two consecutive pool-riffle sequences, includ...

Shale gas resources are abundantly distributed with low porosity and permeability. Horizontal well and fracturing are prior considerations. Fracturing is a widely-used technology to enhance gas production. In this paper, the author (a) investigated the present stimulation of Barnett and Haynesvile gas fields (Fig. 1) in America, Sichuan basin (Fig. 2) in China and Cooper basin (Fig. 3) in Austr...

A modular He-cooled divertor concept for DEMO is being investigated at Forschungszentrum Karlsruhe (FZK) within the framework of the EU power plant conceptual study. The design goal is to reach a heat flux of at least 10 MW/m. The reference design HEMJ (helium-cooled modular divertor with jet cooling) consists of a hexagonal tungsten tile which is brazed to a thimble made of W-1%La2O3. The cool...

Cavitation has been investigated in directional control valves in order to identify damage mechanisms characteristic of components o f aircraft hydraulic systems. Tests have been conducted in a representative metal spool valve and in a model three times larger. Data taken under noncavitating conditions with both valves showed that the position of the high-velocity annular jet shifts orientation...

In this paper, modelling and identification of a hydraulic servoactuator system is presented. The development of the model is important for further understanding the system and for developing a robust force controller. A systems approach is used to model the various subsystems including the servovalve dynamics, fluid dynamics and the vane and load dynamics. Included in the model are line losses...

The k-ω Shear Stress Transport (SST) turbulence model is adopted to study the hydrodynamic performance of the water-jet axial pump which is applied in Unmanned Surface Vehicle (USV). The numerical simulation of the whole passage of the water-jet pump is carried out for four different tip clearance with δ = 0.3 mm, δ = 0.8 mm, δ = 1 mm and δ = 1.4 mm. And the results, in term of external charact...

Designing and manufacturing the multiple jets simulator and experimental investigation of the multiple jets in crossflow at low velocity ratios have been studied Together with design and build a low-speed wind tunnel. A specific rake is used to determine the flow field pressure and changes in static pressure measured by pressure taps in the near field of the jets. There are generally three regi...

In this study, the missile staging process by implementing a side-injected jet is simulated numerically. The problem is considered to be axisymmetric and the thin shear layer approximation of Navier-Stokes equations along with an algebraic turbulence model is used in a quasi-static form for the calculations. The free stream corresponds to a very high altitude flight condition with a Mach number...