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.
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Showing 1 to 20 of 73 for “""turbine blade tip rub""”.
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Understanding the Responses of a Metal and a CMCTurbine Blade during a Controlled Rub Event using a Segmented Shroud
… composites, provide several benefits over metal blades including weight and increased temperature capability, which may save performance by significant reduction of the cooling flow bled from the compressor. The turbine inlet temperature has consistently increased over the past 70-years. …
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Turbine tip clearance loss mechanisms
… design features, and of aspects of the actual turbine environment, on turbine blade tip loss. The calculations were carried out for a subsonic high pressure turbine stage. The loss mechanism examined is that due to tip clearance vortex mixing. The effects examined were three-dimensional blade …
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Effects of Tip Clearance Gap and Exit Mach Number on Turbine Blade Tip and Near-Tip Heat Transfer
… on local heat transfer characteristics on the tip and near-tip regions of a turbine blade with a flat tip, tested 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 …
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Measurements of Cooling Effectiveness Along the Tip of a Turbine Blade
In a gas turbine engine, turbine blades are exposed to temperatures above their melting point. Film-cooling and internal cooling techniques can prolong blade life and allow for higher engine temperatures. This study examines a novel cooling technique called a microcircuit, which combines internal …
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Tip leakage flow in a linear turbine cascade
… performed to study the details of flow in the tip clearance gap of a linear turbine blade cascade. The cascade was designed and built to be geometrically similar to the earlier VPI&SU cascade; however, the new cascade also had a tip gap (2.1 percent of blade height) and two endwall boundary …
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Film Cooling Predictions Along the Tip and Platform of a Turbine Blade
Turbine airfoils are exposed to the hottest temperatures in the gas turbine with temperatures typically exceeding the melting point of the blade material. Cooling methods investigated in this computational study included parasitic cooling flow losses, which are inherent to engines, and microcircuit …
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Loss mechanisms in turbine tip clearance flows
Numerical simulations of tip clearance ow have been carried out to dene the loss generation mechanisms associated with tip leakage in unshrouded axial turbines. Mix- ing loss between the leakage, which takes the form of a strong embedded streamwise vortex (u=ux 1 in the vortex core), and the …
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An experimental investigation of turbine blade tip heat transfer and tip gap flows in the supersonic regime
Gas turbine blade tip heat transfer and tip gap flow phenomena has been explored experimentally in a stationary cascade for blade exit Mach numbers = 1.2 to 1.4. Experimental results were found to agree well with qualitative predictions performed at GE Aircraft Engines. The pressure distribution in …
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Tip leakage loss development in a linear turbine cascade
Tip leakage losses were studied in a linear turbine cascade with a tip clearance gap equal to 2.1 percent of blade height. The blades of the cascade have a turning angle of 109.4 degrees, an aspect ratio of 1.0, and an axial chord length of 235.2 mm. The cascade was located at the exit of a low …
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Tip leakage flow, heat transfer and blade lifing in a jet engine turbine
… calculate developing flow and heat transfer in turbine tip gaps. Successful calculations of the heat transfer to a model turbine blade tip were obtained with a Prandtl mixing length turbulence model. The calculations revealed details of the flow development including recirculation and …
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Tip leakage losses in a linear turbine cascade
An investigation of tip leakage flow and its effects on loss production was performed on a large-scale linear turbine cascade having a tip gap measuring 2.1% of the blade height. The Reynolds number based on axial chord and cascade exit velocity was 4.5x10⁵. The experimental work began with a …
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Reynolds stress measurements in a turbine tip leakage vortex
… study of the structure of turbulence in a tip leakage vortex was conducted in a large scale, linear turbine cascade. The study was performed in a cross sectional plane 0.96 of the axial chord length downstream of the blade leading edge. The cascade consisted of five blades with an aspect …
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Comparison of the Thermal Performance of Several Tip Cooling Designs for a Turbine Blade
Gas turbine blades are subject to harsh operating conditions that require innovative cooling techniques to insure reliable operation of parts. Film-cooling and internal cooling techniques can prolong blade life and allow for higher engine temperatures. This study examines several unique methods of …
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An investigation of flow field perturbation caused by constant blade tip clearance in a turbine
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1990.
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Experimental and Computational Study of Heat Transfer on a Turbine Blade Tip with a Shelf
Cooling of turbine parts in a gas turbine engine is necessary for operation as the temperature of combustion gases is higher than the melting temperature of the turbine materials. The gap between rotating turbine blades and the stationary shroud provides an unintended flow path for hot gases. Gases …
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Experimental Study of the Heat Transfer on a Squealer Tip Transonic Turbine Blade with Purge Flow
… and heat transfer distribution of a squealer tip rotor blade with purge flow cooling and provide a comparison with a basic flat tip rotor blade without purge flow cooling, under transonic conditions and high inlet free stream turbulence intensity. The blade design was provided by Solar …
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Design, Analysis, Optimization and Control of Rotor Tip Flows
… investigations over the past decades, the turbine tip design presents numerous challenges to the engine manufacturers, and remains the primary factor defining the machine durability for the periodic removal of the turbine components during overhaul. Due to the hot gases coming from the …
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Vertical axis wind turbine with continuous blade angle adjustment
… presents a concept for a vertical axis wind turbine that utilizes each blade's entire rotational cycle for power generation. Each blade has its own vertical axis of rotation and is constrained to rotate at the rate of one half of a revolution per full revolution of the rotor. For a rotor of …
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Effects of axial turbine tip shroud cavity flow on performance and durability
Flow through tip shroud cavity in a representative axial turbine vane-rotor stage environment is assessed for its role in loss generation and turbine durability. Steady and unsteady three-dimensional flow computations, complemented by control volume analyses, for varying shroud configurations …
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