Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"Aerodynamic Loss"”.
-
The effect of blade solidity on the aerodynamic loss of a transonic turbine cascade
Past research at Virginia Tech (VPI) explored the aerodynamic loss of the transonic VPI turbine blade, which 1s based on the pitchline profile of a high pressure turbine blade for a large commercial aircraft gas turbine. The current experiment explores the loss of the VPI blade for different axial …
-
An experimental study on the effects of blade row interactions on aerodynamic loss mechanisms in a multistage compressor
… existed for nearly 80 years, much of the complex aerodynamics which governs compressor performance is still not well understood. The unsteady flow field consists of periodic blade row interactions from the wakes and potential fields of each blade and vane. Vane clocking is the relative …
-
Heat Transfer, Transition, And Aerodynamic Loss In A Linear Vane Cascade At Low Reynolds Numbers In High Speed Flows
… often leads to enhanced profile and secondary losses, which reduces turbine efficiency. Previous research conducted on low pressure turbine flow conditions, has investigated heat transfer, boundary layer separation bubbles, and secondary flows subjected to varying levels of freestream …
-
Aerodynamic performance of a transonic turbine blade passage in presence of upstream slot and mateface gap with endwall contouring
The present study investigates mixed out aerodynamic loss coefficient measurements for a high turning, contoured endwall passage under transonic operating conditions in presence of upstream purge slot and mateface gap. The upstream purge slot represents the gap between stator-rotor interface and …
-
Aerodynamics of Endwall Contouring with Discrete Holes and an Upstream Purge Slot Under Transonic Conditions with and without Blowing
… studied as an effective measure to improve aerodynamic performance by reducing secondary flow strength. The effects of endwall contouring with discrete holes and an upstream purge slot for a high turning (127") airfoil passage under transonic conditions are investigated. The total pressure …
-
Characterization and design of non-adiabatic micro-compressor impeller and preliminary design of self-sustained micro engine system
… points penalty) and (iii) passage boundary layer loss (10 points penalty). The magnitude of the first effect is a result of the engine small length scale selection and is characterized by the total heat to impeller flow as fraction of inlet flow enthalpy. The magnitudes of the last two effects can …
-
The Effect of Endwall Contouring On Boundary Layer Development in a Turbine Blade Passage
… as a significant contributing factor to aerodynamic loss and increased part temperatures. Three-dimensional (non-axisymmetric) contouring of the endwall surface has been shown to reduce aerodynamic losses, but the effect of the contouring on endwall heat transfer is not well understood. …
-
Effects of Mach Number and Flow Incidence on Aerodynamic Losses of Steam Turbine Blades
An experiment was conducted to investigate the aerodynamic losses of two high-pressure steam turbine nozzles (526A, 525B) subjected to a large range of incident angle and exit Mach number. The blades were tested in a 2D transonic windtunnel. The exit Mach number ranged from 0.60 to 1.15 and the …
-
Real gas effects in ORC turbines
… the given range of isentropic exponents, the loss can vary between 20% and 35%, depending on vane exit Mach number. These difference in aerodynamic loss are driven by a change in the mixing loss at the trailing edge loss and a shift in shock loss within the passage. These effects are a strong …
-
Thermofluid design and analysis of centrifugal compressors for a 50 MWe concentrated solar power supercritical CO₂ Brayton power cycle
… Skin friction was identified as the predominant aerodynamic loss mechanism within the rotor. The exhaustive search mean line preliminary design approach provided valuable insights into the influence of different parameters on the performance of each of the machines, while the good agreement …
-
Aerodynamic Performance of High Turning Airfoils and the Effect of Endwall Contouring on Turbine Performance
… cost and weight, they also result in increased aerodynamic losses and associated issues. The strength of secondary flows is influenced by the upstream boundary layer thickness as well as the overall flow turning angle through the blade row. Secondary flows result in stagnation pressure loss …
-
Aerothermal Sentencing for Manufacturing Variations on Turbine Blade Shrouds
… (Q2D) aftchord region, a step heat transfer and loss correlation is developed using a parametric study on a Q2D model of the shroud endwall. The heat transfer correlation calculates the Nusselt number at the reattachment point as a function of the included parameters. The change in total pressure …
-
Development of a robust numerical optimization methodology for turbine endwalls and effect of endwall contouring on turbine passage performance
… past two decades for the reduction of secondary losses in turbine passages. Although many endwall contouring methods have been suggested by researchers, an analytical tool based on the passage design parameters is still not available for designers. Hence, the best endwall contour shape is usually …
-
Effects of Free Stream Turbulence on Compressor Cascade Performance
… was the behavior of the measured total pressure loss coefficient with and without generated free-stream turbulence. A staggered cascade of nine airfoils was tested at a range of Mach numbers between 0.59 and 0.88. The airfoils were tested at both the lowest loss level cascade angle and extreme …
-
Aerodynamic Performance of a Flow Controlled Compressor Stator Using an Imbedded Ejector Pump
… by measuring the reduction in the total pressure loss coefficient. The experiment was conducted in a linear transonic blowdown cascade wind tunnel. The inlet Mach number for all tests was 0.79, with a Reynolds number based on stator chordlength of 2,000,000. A range of inlet cascade angles was …
-
Effects of Flow Control on the Aerodynamics of a Tandem Inlet Guide Vane
An aerodynamic investigation was performed to assess the effectiveness of combined boundary layer suction and trailing edge blowing at reducing the blade profile losses and the wake momentum deficit of a cascade of tandem IGV's operating at realistic flow conditions. Two trailing edge blowing …
-
The Effect of Freestream Turbulence on Separation at Low Reynolds Numbers in a Compressor Cascade
… evaluated through mass-averaged total pressure loss coefficients. The results of the study showed that the best efficiency (lowest pressure loss coefficient) was determined by separation characteristics for any angle of attack. While adding turbulence generally delayed separation, in some cases, …
-
Flow Control Optimization for Improvement of Fan Noise Reduction
… coefficient. CFD showed the TEJ and SSJ offered aerodynamic improvement over the Slot configuration. Testing showed the SSJ outperformed the TEJ, as validated in CFD, producing wider and shallower wakes. SSJ area-averaged pressure losses were 25% less than TEJ at design. Noise predictions based …