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Showing 1 to 20 of 44 for “"linear cascade"”.
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Scattering of an entropy disturbance into sound by a linear cascade of turbine stator blades
It is known that modern turbofan engines produce more noise from their exhaust than can be accounted for by jet noise alone. Part of the extra noise coming from the exhaust of the engine is associated with the combustor. Apart from direct combustion noise, the combustor is known to have an indirect …
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Correlation between Unsteady Loading and Tip Gap Flow Occurring in a Linear Cascade with Simulated Stator-Rotor Interaction
… a study performed in the Virginia Tech low speed linear cascade wind tunnel operating at a Reynolds number of 382,000 designed to model an axial compressor rotor. To simulate the flow created by the junction of a set of inlet guide vanes and the compressor casing, vortex generators were glued to a …
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Development of a geometric model for the study of propagating stall inception based on flow visualization in a linear cascade
Flow visualization movies of flow through a cascade of compressor blades showed propagating stall at stagger angles of 36.5 and 45 degrees for angles of attack of 20 degrees and higher. At a stagger angle of 25 degrees, the development of a steady, separated boundary layer occurred with no …
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Effects of shock wave passing on turbine blade heat transfer in a transonic turbine cascade
… The experiments were performed in a transonic linear cascade which matched engine Reynolds number, Mach number, and shock strength. Unsteady heat flux measurements were made with Heat Flux Microsensors on both the pressure and suction surfaces of a single blade passage. Unsteady static pressure …
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Near Wall Behavior of Vortical Flow around the Tip of an Axial Pump Rotor Blade
… of three-dimensional turbulent tip gap flow in a linear cascade wind tunnel with 3.3% chord tip clearance with and without moving endwall simulation. Experimental measurements have been completed in Virginia Tech low speed linear cascade wind tunnel. A 24" access laser-Doppler velocimeter (LDV) …
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An Optically-Pumped Frequency Stable Tunable Maser and Infrared-Microwave Double-Resonance Experiments in Ammonia
Microwave emission attributed to a linear cascade effect has been observed from ('14)NH(,3) optically pumped by a CO(,2) laser. The emission is tunable over the saturated homogeneous linewidth of the ground state sQ(5,4) inversion transition at 22.653 GHz. The circulating power density of the …
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Large Tip Clearance Flows in High Pressure Stages of Axial Compressors
… investigations of large tip clearance in a linear cascade have been used to investigate this phenomenon. Two cascade builds have been used the first (Build A) consisted of a controlled diffusion aerofoil of low stagger and thirty degrees flow turning. The second cascade (Build B) consisted …
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Some Features of Tip Gap Flow Fields of a Linear Compressor Cascade
… three-dimensional turbulent tip gap flows in the linear cascade wind tunnel, for two different tip gap clearances (t/c=1.65% and 3.3%). The experiments focus on near-wall flow field measurements for the stationary wall and moving wall, and static pressure measurement on the low end-wall for the …
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Steady and Unsteady Heat Transfer in a Film Cooled Transonic Turbine Cascade
… on downstream rotor blades is modeled in a linear cascade. The Reynolds number based on blade chord and exit conditions (5*10^6) and the exit Mach number (1.2) are representative of modern engine operating conditions. The relative motion of shocks and blades is simulated by sending a shock …
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Effects of multiple incident shock waves on the flow in a transonic turbine cascade
… a rotating disk with radial bars upstream of a linear cascade. An alternate method of shock generation is developed here using a capped shock tube with multiple outlets to get a traveling system of three shock waves. Different lengths of tubing are used to get time delays between the shocks, …
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Effects of Tip Clearance Gap and Exit Mach Number on Turbine Blade Tip and Near-Tip Heat Transfer
… under transonic conditions in a stationary, 2-D linear cascade consisting of seven blades, the three center blades having a variable tip clearance gap. The effects of tip clearance and exit Mach number on heat transfer distribution were investigated on the tip surface using a transient infrared …
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Experimental and numerical investigations of the off-design flow physics in a supersonic through-flow fan cascade
… turbulent character of the supersonic wake of a linear cascade of fan airfoils has been studied experimentally using a two-component Laser Doppler Anemometer. The cascade was tested in the Virginia Polytechnic Institute and State University intermittent wind tunnel facility, where the …
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Investigation of Aerodynamic Profile Losses for a Low-Reaction Steam Turbine Blade
This thesis presents the results of a linear cascade experiment performed on the mean-line and near-tip sections of a low-reaction steam turbine blade and compares them to CFD of the former. The purpose of these tests was the refinement of a proprietary empirical profile loss model. A review of the …
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Active control of tip clearance flow in axial compressors
… compressor tip clearance flows is explored in a linear cascade using three types of fluidic actuators; Normal Synthetic Jet (NSJ; unsteady jet normal to the mean flow with zero net mass flux), Directed Synthetic Jet (DSJ; injection roughly aligned with the mean flow), and Steady Directed Jet …
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Trailing-Edge Blowing of Model Fan Blades for Wake Management
… of trailing-edge blowing were tested in a linear cascade configuration. Measurements were made on two sets of blowing blades installed in the Virginia Tech low-speed linear cascade wind tunnel. The simple blowing blades were identical to the baseline GE Rotor B blades, aside from a slight …
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Large Eddy Simulation of Shear-Free Interaction of Homogeneous Turbulence with a Flat-Plate Cascade
… of large scale turbulence with a flat-plate cascade is a model of important problems in propulsion systems. Addressing the problem of large scale turbulence interacting with a flat plate cascade requires flow simulation over a large number of plates (6-12 plates) in order to be able to …
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Aerodynamics of Endwall Contouring with Discrete Holes and an Upstream Purge Slot Under Transonic Conditions with and without Blowing
… The experiments were performed in a quasi-2D linear cascade with measurements at design exit Mach number 0.88 and incidence angle. Four cases were analyzed for each endwall -- the effect of slot presence (with/without coolant) and the effect of discrete holes (with/without coolant) without …
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Experimental and Computational Study of Heat Transfer on a Turbine Blade Tip with a Shelf
… were performed in a low speed wind tunnel on a linear cascade with two different tip gaps and multiple coolant flow rates through the film-cooling holes. Tests showed that baseline Nusselt numbers on the tip surface were reduced with the shelf tip compared with a flat tip. Measurements indicated …
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Effect of Blowing Ratio on the Nusselt Number and Film Cooling Effectiveness Distributions of a Showerhead Film Cooled Blade in a Transonic Cascade
… The blade was arranged in a two-dimensional, linear cascade within a transonic, blowdown type wind tunnel. The wind tunnel freestream conditions were varied over two exit Mach numbers, Me=0.78 and Me=1.01, with an inlet freestream turbulence intensity of 12% , with an integral length scale …
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Generation of Downstream Vorticity Through the Use of Modified Trailing Edge Configurations
… streamwise velocity into the flow behind a cascade of GE Rotor B fan blades. These measurements were conducted in the Virginia Tech Low Speed Linear Cascade wind tunnel. The trailing edge configurations tested utilized passive techniques for producing streamwise vorticity, which in turn …
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