For decades, researchers have worked towards developing a suitable model to represent turbulent boundary layers. Based on PIV experiments in the x − z planes of a turbulent boundary layer, Adrian et al. [1] proposed a model based on a packet of “hairpin vortices” as a primary feature in turbulence transport and production (In this paper, streamwise, spanwise and wall-normal directions are along...

Recent experiments have shown that spreading epithelial sheets exhibit a long-range coordination of motility forces that leads to a buildup of tension in the tissue, which may enhance cell division and the speed of wound healing. Furthermore, the edges of these epithelial sheets commonly show finger-like protrusions whereas the bulk often displays spontaneous swirls of motile cells. To explain ...

BACKGROUND There has been much debate about the orientation of multi-hair grafts in order to obtain an appearance of fullness after the hair transplantation. OBJECTIVES To analyze natural orientation of multi-hair follicles and the influence of hair flow from the crown swirl. METHODS Natural orientation of follicles was analyzed microscopically in 100 nonbald men: a clockwise whorl flow gro...

In this paper a detailed model of a VVER1000 reactor pressure vessel (RPV) with the extension of simplified primary loops is presented (Loop model). The primary loop components like steam generators and pumps are modelled by the outer shapes and additional source terms for energy and momentum exchange. The RPV model part is tested without primary loops and compared with former results obtained ...

Regarding the power, the efficiency and the discharge questions of the low-speed diesel engine, this article studied emphatically the Miller cycle, the analysis technology for the air intake system, and the matching technology for the intake and the exhaust. On the foundation of the twin inlet structure the paper analyzed the intake swirl control area and its influence to the gas charging effic...

The present work considers the turbulent air flow inside an annular high speed rotor-stator cavity opened to the atmosphere at the periphery. The interdisk-spacing is sufficiently large so that the boundary layers developed on each disk are separated and the flow belongs to the regime IV of Daily and Nece (1960). In such a system, the solid body rotation of the core predicted by Batchelor in ca...

There is considerable interest in developing fuel-flexible, low emissions turbines for power generation. One approach is based on burning a variety of lean premixed fuels with relatively low flame temperatures. Such flames can be stabilized in a low swirl burner configuration, for example, using a variety of fuels such as pure hydrogen and hydrogen-seeded hydrocarbon mixtures. However, many hyd...

Abstract The objective of this work is to describe and validate a numerical axisymmetric approach for the simulation hybrid rocket engines (HREs), based on Reynolds-averaged Navier–Stokes simulations, with sub-models fluid–surface interaction, radiation, chemistry, turbulence. Fuel grain consumption considered both radial axial directions swirl injection oxidizer are simulated. Firing tests two...

In new generation aero-engines, lean-burn combustors are equipped with swirl injectors in order to reduce pollutant emissions. At the exit of these combustors, flow is dominated by temperature non-uniformity (hot-streak) and residual swirl. Available research has focused mainly on isolated effects only or hot-streak aerodynamic performance thermal high-pressure turbine (HPT). Only few studies i...