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Total pressure
About: Total pressure is a research topic. Over the lifetime, 5199 publications have been published within this topic receiving 66658 citations.
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TL;DR: In this paper, the authors describe a portion of an experimental and computational program (ADLARF), which incorporates measurements of all aspects of the forced response of an airfoil row, i.e., the flow defect, the unsteady pressure loadings, and the vibratory response.
Abstract: This paper describes a portion of an experimental and computational program (ADLARF), which incorporates, for the first time, measurements of all aspects of the forced response of an airfoil row, i.e., the flow defect, the unsteady pressure loadings, and the vibratory response. The purpose of this portion was to extend the knowledge of the unsteady aerodynamics associated with a low-aspect-ratio transonic fan where the flow defects were generated by inlet distortions. Measurements of screen distortion patterns were obtained with total pressure rakes and casing static pressures. The unsteady pressure loadings on the blade were determined from high response pressure transducers. The resulting blade vibrations were measured with strain gages. The steady flow was analyzed using a three-dimensional Navier-Stokes solver while the unsteady flow was determined with a quasi-three-dimensional linearized Euler solver. Experimental results showed that the distortions had strong vortical, moderate entropic, and weak acoustic parts. The three-dimensional Navier-Stokes analyses showed that the steady flow is predominantly two-dimensional, with radially outward flow existing only in the blade surface boundary layers downstream of shocks and in the aft part of the suction surface. At near resonance conditions, the strain gage data showed blade-to-blade motion variations and thus, linearized unsteady Euler solutionsmore » showed poorer agreement with the unsteady loading data than comparisons at off-resonance speeds. Data analysis showed that entropic waves generated unsteady loadings comparable to vortical waves in the blade regions where shocks existed.« less
38 citations
TL;DR: The X-type pseudo-shock was investigated in this article, which appeared at comparatively high Mach number, and was compared with the λ-type Pseudo-Shaking reported in the previous paper.
Abstract: The X-type pseudo-shock was investigated, which appeared at comparatively high Mach number, and was compared with the λ-type pseudo-shock reported in the previous paper. The similarity and difference between them were discussed. At the duct center, the shock loss by the leading shock wave is smaller for the X-type pseudo-shock than for the λ-type one, but near the wall and in the subsonic region, the flow conditions are similar. The over-all total pressure loss is affected by the mixing of the flow near the wall with the main stream and the so-called shock loss is rather small. the effect of the boundary layer and the wall friction force on the static pressure rise of the pseudo-shock is also made clear. The simple model for the mechanism of the pseudo-shock is presented in the appendix.
38 citations
TL;DR: In this paper, a mathematical model was developed that describes pressure losses taking into account the rearrangement of a velocity profile in liquid slugs and energy losses on the formation and renewal of interfacial area during the motion of bubbles.
Abstract: In addition to the previously constructed model of the hydrodynamics of a gas-liquid slug flow, a mathematical model is developed that describes pressure losses taking into account the rearrangement of a velocity profile in liquid slugs and energy losses on the formation and renewal of interfacial area during the motion of bubbles. The contribution of different forms of pressure losses in capillaries is analyzed. It is shown that in microchannels tangential stresses on the surface of a bubble substantially affect the total pressure losses. It is found that the length of bubbles does not affect the rate of surface formation and respective pressure losses if bubbles have the same velocity. The results of modeling are in satisfactory agreement with experimental data of other researchers.
37 citations
10 Jun 1996
TL;DR: In this paper, a 3D Navier-Stokes solver was used to determine the steady flow and the unsteady flow with a quasi-3D linearized Euler solver.
Abstract: This paper describes a portion of an experimental and computational program (ADLARF) which incorporates, for the first time, measurements of all aspects of the forced response of an airfoil row, i.e., the flow defect, the unsteady pressure loadings and the vibratory response. The purpose of this portion was to extend the knowledge of the unsteady aerodynamics associated with a low aspect ratio transonic fan where the flow defects were generated by inlet distortions. Measurements of screen distortion patterns were obtained with total pressure rakes and casing static pressures. The unsteady pressure loadings on the blade were determined from high response pressure transducers. The resulting blade vibrations were measured with strain gages. The steady flow was analyzed using a 3D Navier–Stokes solver while the unsteady flow was determined with a quasi–3D linearized Euler solver.Experimental results showed that the distortions had strong vortical, moderate entropic and weak acoustic parts. The 3D Navier–Stokes analyses showed that the steady flow is predominantly two–dimensional, with radially outward flow existing only in the blade surface boundary layers downstream of shocks and in the aft part of the suction surface. At near resonance conditions, the strain gage data showed blade–to–blade motion variations and thus, linearized unsteady Euler solutions showed poorer agreement with the unsteady loading data than comparisons at off–resonance speeds. Data analysis showed that entropic waves generated unsteady loadings comparable to vortical waves in the blade regions where shocks existed.Copyright © 1996 by ASME
37 citations
TL;DR: In this paper, the effects of low total pressure on gas exchange rates of spinach plants were investigated, and it was found that the gas exchange rate of plants grown under low-total pressure was not increased even with the enhancement of gas diffusion.
37 citations