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Showing 1 to 20 of 26 for “"Hotwire"”.
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Hotwire measurements of the turbulent flow into a cascade of controlled-diffusion compressor blades
… made in a subsonic cascade wind tunnel with a hotwire system. Using a single hot-film probe, velocity and turbulence distortion data were obtained about the leading edge of the Controlled-Diffusion (CD) blades in order to verify Laser Doppler Velocimetry (LDV) data taken in earlier studies. …
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Development and application of transition detection using infrared thermography for characterization of fan blade waviness effects
… from infrared images is assessed against hotwire measurement which establishes transition location based on the growth of Tollmien-Schlichting waves in the boundary layer. Infrared thermography is used to determine the effects of surface waviness on natural transition in the regime of …
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Measurement of three-dimensional horseshoe vortex flow in a duct
… measurement technique using a single slanted hotwire anemometer is evaluated. The hotwire anemometer measurements are compared with measurements of the same flow made with a five-hole pressure probe. A two-dimensional laminar and turbulent boundary layer analysis is performed at mid-height on …
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Effect of Adaptive Tabs on Drag of a Square-Base Bluff Body
… measurements, total drag force measurements and hotwire velocity fluctuation measurements. These tests were repeated with tabs on the model’s trailing edge at the three different tab heights and without tabs at all three test speeds.</p> <p>The base pressure measurements showed a decrease in …
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Aerodynamics and aeroacoustics of flap side-edges
… pressures, particle image velocimetry, hotwire anemometry and on-surface microphones. Oil flow was performed to visualise the on-surface flow. A detached eddy simulation was performed on a geometry that consisted of a main element and a half span flap to understand the flowfield. From …
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The Enhancement of Convective Heat Transfer in an Aluminum Oxide Nanoaerosol
Hotwire experiments were performed to assess the effects of suspended 112 nm diameter aluminum oxide (Al2O3) nanoparticles in air on the rate of convective heat transfer. The particle mass loading was varied over a range of flow Reynolds number. The results indicate up to a 36% increase in Nusselt …
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Thermal conductivity of fluids containing suspension of nanometer-sized particles
… base fluids were conducted with the transient hotwire technique. Results show that the thermal conductivity enhancement of nanofluids increases with particle volume concentration, with higher thermal conductivity enhancement observed for ethylene glycol than deionized water base fluids. …
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Active and Passive Flow Control over the Flight Deck of Small Naval Vessels
… the ship's flight deck using a single component hotwire. Results show that the use of porous surfaces decreases the unsteadiness of the flow field. Further improvements are found by injecting air through these porous surfaces, causing a reduction in unsteadiness in the landing region of 6.6% at 0 …
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Effect of wall motion on a two-dimensional turbulent boundary layer
… of the freestream. Velocity measurements, using hotwire anemometry, are carried out at various locations upstream, on and downstream of the moving belt. A standard TSI boundary-layer probe is used. Mass transfer measurements are conducted using a naphthalene-coated sublimation plate, placed …
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Inlet flow-field measurements of a transonic compressor rotor prior to and during steam-induced rotating stall
… prior to and during a steaminduced stall. Hotwire measurements of the inlet flow field were taken to determine an inlet turbulence intensity of 2-3% during both subsonic as well as transonic compressor operation. A 95% speed line was established from data taken from open throttle to near …
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Design and Evaluation of an Active Yaw and Turbulence Generation System to Produce Unsteady Flow in Automotive Wind Tunnels
… velocity data were obtained using two-component hotwire anemometry measurements that were spatially averaged. Yaw performance under different operating conditions, such as flap oscillation frequency and amplitude, was evaluated in terms of the phase-averaged flow behavior, the shape of the yaw …
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Wind tunnel study of wind farms with alternating 2- and 3-bladed wind turbines
… velocity measurements were made with hotwire anemometry at various locations in the wake and the power output of turbines was measured simultaneously. Comparison of the flow between an array with only 3BT and that with alternating 2BT and 3BT shows enhanced mean velocity and reduced …
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Interaction of High Aspect-Ratio Micro-Pillars with Wall Turbulence
… of HAMuP arrays with wall turbulence. Hotwire anemometry measurements were carried out in two different experimental facilities at three different streamwise locations to describe the interaction between the HAMuP array and the wallturbulence. There is a shift of the laminar sublayer …
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Experimental investigation of the effects of upstream perturbations in the near-wall and core of a high porosity random-wire porous medium.
… to travel unperturbed through the porous medium. Hotwire measurements of velocity were taken at the exit of the test-section, which provided insight on the characteristics of transport in different regions of the porous medium. It was discovered that pore-scale eddies, shed from the mental wires …
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Microstructure and residual stress in hydrogenated amorphous silicon (a-Si:H) layers
… diffraction. The a-Si:H layers were deposited by hotwire chemical vapour deposition (HW -CVD) on a glass substrate at a growth temperature of 300°C and 500°C, respectively. The microstructural state from the diffraction phase has been experimentally determined using the pair correlation function, …
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Jet oscillation applied for aircraft cabin ventilation using active flow control actuators
… the major method of studying cabin airflow while hotwire measurement and flow visualization are made to validate the modelling of the synthetic jet. The fresh air jet entering the cabin is seen to oscillate about its injection angle when the supply flow rate experiences a series of sudden changes. …
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Passive methods for suppressing acoustic resonance excitation in shallow rectangular cavities.
… mechanism introduced by these passive methods, hotwire measurements are performed revealing the existence of orthogonal vortices interacting with the shear layer at the cavity mouth. The second passive method investigated is the effect of placing a high frequency vortex generator (control …
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The spectral characteristics of wind-farm power output
… Incoming flow turbulence was characterized by hotwire and sonic anemometers for the wind tunnel and field setups. While previous works have observed a filtering behavior in wind turbine power output, this exact behavior has not, to date, been properly characterized. Based on the spectral …
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Pressure Fluctuations in a High-Reynolds-Number Turbulent Boundary Layer over Rough Surfaces of Different Configurations
… were made using pinhole microphones and hotwire measurements were made to obtain the velocity and turbulence field. Among the principal findings is the development of two scaling laws for the low frequency pressure fluctuations. Both of these are based on the idea that the defect between …
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Development of a new apparatus to measure flame spread through a free stratified fuel/air mixture: numerical modeling and experimental results
… to ensure a steady, laminar quality, as well as hotwire anemometer and thermocouple scans to measure velocity and temperature profiles, respectively; all of these agreed with model predictions.</p> <p>Preliminary experimental results show that it is possible to obtain a propagating flame in a …
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