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 24 for “"Aerothermal"”.
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Probabilistic aerothermal design of compressor airfoils
… little is known in detail about its impact on aerothermal compressor performance. In this work, statistical and probabilistic techniques were used to assess the impact of geometric and operating condition uncertainty on axial compressor performance. High-fidelity models of geometric variability …
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Probabilistic aerothermal design of gas turbine combustors
This thesis presents a probability-based framework for assessing the impact of manufacturing variability on combustor liner durability. Simplified models are used to link combustor liner life, liner temperature variability, and the effects of manufacturing variability. A probabilistic analysis is …
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Aerothermal Sentencing for Manufacturing Variations on Turbine Blade Shrouds
… well-matched to the corresponding influence on aerothermal performance caused by the geometric deviation. If this condition is not fulfilled, this can lead to well-performing parts costing around $8000 being scrapped and suboptimal parts being used in service, which can trigger an early shop …
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On Aerothermal Optimization of Low-Pressure Steam Turbine Exhaust System
This thesis addresses two challenges in the aerothermal optimization of Low-Pressure Steam Turbine Exhaust System (LPES). The first one is the high computational cost due to the complexity of LPES geometry. To make things worse, designers have to consider extra cost caused by change of constraints, …
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Impact of parametric aerothermal variability on aircraft engine operating cost
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2002.
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Impact of aerothermal modeling on the estimation of turbine blade life
The impact of aerothermal modeling on estimates of turbine blade heat transfer and life was assessed for three high pressure turbine blades. The work was conducted as part of a project aimed at the evaluation of the effect of variability on turbine life. Pressure and thermal loads were extracted …
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High-Fidelity Computational Analysis of the Aerothermal Performance of In-serviced Jet Engine Blades
In today’s civil aviation, the struggle for higher jet engine efficiencies has pushed the manufactures into the continuous challenge of developing new and better design and optimization strategies. In the information age, it is only natural that a great deal of this effort is going to be carried …
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Aerothermal and aeroelastic response prediction of aerospace structures in high-speed flows using direct numerical simulation
… dynamic loading from multiple sources such as aerothermal heating, propulsion system exhaust, and high dynamic pressures. The combination of low-margin design requirements and extreme environmental conditions emphasizes the occurrence of fluid-thermal-structural coupling. Numerous attempts to …
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Experimental Investigation of Initial Onset of Sand Deposition in the Turbine Section of Gas Turbines
… for turbomachinery. Experiments have been in an Aerothermal Rig facility at Virginia Tech to study particle deposition at engine representative temperatures. The Aerothermal Rig was upgraded to achieve air temperatures of up to 1100°C at the test section. The experiments are performed using …
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Technique for Measuring the Coefficient of Restitution for Microparticle Sand Impacts at High Temperature for Turbomachinery Applications
… Laser-Camera system is used in the Virginia Tech Aerothermal Rig to measure microparticles velocity. The method solves for particle impact velocity at the surface by numerical methods. The methodology presented here characterizes a difficult problem by a combination of established techniques, PTV …
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Infrared Thermography Techniques for Flow Visualisation and Heat Transfer Coefficient Measurement
… knowledge of the boundary layer state on an aerothermal component is critical for predicting loss and heat transfer in design. Despite this importance, practical computational methods that predict boundary layer state remain unreliable thanks to the sparse, scattered data on which they are …
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Effect of Temperature on Microparticle Rebound Characteristics at Constant Impact Velocity
… presents data taken using the Virginia Tech Aerothermal Rig. Arizona Road Dust (ARD) of 20-40 μm is injected into a flow field to measure the effects of temperature and velocity on particle rebound from a polished high temperature material coupon. The high temperature coupon was tested at …
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Numerical Treatment of Schrödinger’s Equation for One-Particle and Two-Particle Systems Using Matrix Method
… an increased interest in accurately predicting aerothermal environments for planetary entry, recent researches have concentrated on developing high fidelity computational models using quantum-mechanical first principles. These calculations are dependent on solving the Schrödinger equation using …
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Heat Transfer and Flow Characteristics on the Rotor Tip and Endwall Platform Regions in a Transonic Turbine Cascade
… experimental and numerical analysis of the aerothermal characteristics of the turbine extremity regions i.e. the blade tip and endwall regions. The heat transfer and secondary flow characteristics were analyzed for different engine relevant configurations and exit Mach/Reynolds number …
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High-Temperature Performance of Carbon Fiber Reinforced Cyanate Ester Composites Filled with Nano-Ceramics
… loss and char yield of different formulations. Aerothermal ablation testing is conducted to evaluate the nanocomposites under a high heat flux of 1,000 W/cm2 by the Oxy-acetylene Test Bed (OTB) as per ASTM E 285. The objective of this research is to determinate if a nanomodification of cyanate …
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Aero-thermal-mechanical interactions in ultra high-speed micro gas turbines
… non-dimensional parameters characterizing the aerothermal-mechanical interaction and response are identified using a reduced order model that yields thermal-induced mechanical deformation in agreement with the unsteady computations. For geometrically similar engine system, the controlling …
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Characterization of carbon ablators for hypersonic thermal protection systems
… (TPS). Ablative materials, which dissipate aerothermal energy through controlled decomposition, are a commonly selected TPS material, with carbon-based variants often preferred for their superior thermochemical performance at high temperatures. Understanding how these materials decompose …
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Coupling of Fluid & Solid Thermal Models to Correct Heat Flux Measurements Taken on Launch Vehicles
<p>Knowledge of aerothermally induced convective heat transfer and plume induced radiative heat transfer loads is essential to the design of thermal protection systems (TPS) for launch vehicles. These loads are measured via the cylindrical heat flux gauges that are flush mounted with the outer …
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Experimental Investigation of Microparticle Sand Sticking Probability from 1000°C to 1100°C
… and aerosol densities. The Virginia Tech Aerothermal Rig was used for all test scenarios at flow-particle temperatures between 1000°C to 1100°C. Several statistical models were developed as a function of many independent variables, culminating with a final sticking probability (SP) model. …
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