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 20 of 35 for “"blade geometry"”.
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Blade geometry description using B-splines and general surfaces of revolution
… for the geometric description of turbomachinery blades. Many of the techniques presented are new and cannot be found in the literature. The geometry construction process is broken into several steps. Each of these steps has variations that constrain different design parameters, enabling …
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An image processing technique for erosion analysis on compressor blade geometry
… implications; largely due to compressor blade material erosion. Current methods for monitoring this erosion (such as visual tools) lack adequate reliability and consistency, while only providing qualitative insight into changes in blade geometry. This study presents a novel application …
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Influence of Reynolds number and blade geometry on low pressure turbine performance
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1997.
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Determining appropriate loss coefficients for use in the nozzle-model of a stage-by-stage turbine model
… turbine modelling methodology, requiring minimal blade passage information, produced a customizable turbine stage component. This stage-by-stage turbine nozzlemodel component was derived from the synthesis of classical turbine theory and classical nozzle theory enabling the component to accurately …
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Robust design and tolerancing of compressor blades
Variations in the geometry of compressor blades can be introduced by variability in the manufacturing process or by in-service erosion. Recent research efforts have focused on characterizing the impacts of this geometric variability on turbomachinery performance and designing blade geometries whose …
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Analytical method for turbine blade temperature mapping to estimate a pyrometer input signal
… thesis is to develop a method to estimate local blade temperatures in a gas turbine for comparison with the output signal of an experimental pyrometer. The goal of the method is to provide a temperature measurement benchmark based on a knowledge of blade geometry and engine operating conditions. …
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Synergistic diffuser/heat-exchanger design
… extraction sensitivities to cooling and annular blade geometry variations. Results show promising diffusion and heat-transfer capabilities that match or surpass current design performance. Proposed configurations are outlined based on these results that compare favorably to a baseline industrial …
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Studies of Multipoint Optimization of Transonic Stators
… and 17% faster than K-ε. Variable stator blades were added to an optimized blade geometry and compared to a design case where the stator blade angle was a part of the design vector. The optimized blade without variable stator blades was able to reduce total pressure loss to be 66.5% of the …
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Body Force Modeling for Engine Inlet Fan System
… using source terms to model the effects of fan blades. The method is designed to capture interaction effects between bypass fan and nacelle at off-design conditions, especially for circumferential inlet distortions. The unique feature of this body force model compared to conventional throughflow …
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A finite difference solution to the two-dimensional wall jet on a combustion turbine blade
… edge of a representative combustion turbine blade. The blade geometry is developed by distributing a standard airfoil section over a single-parabolic camber line.
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An Automated Optimal Design of a Fan Blade Using an Integrated CFD/MDO Computer Environment
… parameters that describe the three-dimensional geometry of the blade while applying performance and geometrical constraints on blade shapes that are investigated. The optimal design is defined as the blade geometry which produces the maximum total efficiency subject to specified constraints on …
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Design and construction of a propeller open water testing apparatus and testing of a stereolithography 3D printed model propeller
… as size constraints and imprecision of propeller blade geometry. This research has provided MIT students with an inexpensive method to conduct preliminary marine propeller testing and offers in-sight into the use of additively manufactured model propellers.
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A 3-d model for the operation of a radiation pyrometer in an axial flow turbine
An accurate knowledge of turbine blade surface temperature is desired in order to obtain maximum performance from turbine engines. A limited spectrum radiation pyrometer can be used for blade temperature measurement. A model is presented which predicts the output signal from the detector unit of a …
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Design Optimization of the First Stage Fan Blade of a Low Bypass Turbofan Engine
… analyzing the aerodynamics, thermodynamics, and blade geometry across the first stage rotor blade under an extreme set of conditions, while altering several design parameters, has been developed and applied. The conditions for which the analyses have been developed were designed for the use of, …
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Robust design methodologies: application to compressor blades
Compressor blades are subtle aerodynamic shapes designed after years of research and insight. They inevitably show deviations from their desired shapes due to manufacturing errors, erosion or foreign object damage. In the present study we focus on seeking compressor blade geometries, that are …
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Incorporation of High-Fidelity Flow Field Information into Preliminary Design of Multi-Stage Axial Compressors
… of changes in radial non-uniformity and in blade geometry on the axisymmetric flow field. The approach can supersede current throughflow methods, increasing the fidelity of preliminary design. The primary impact of the methodology is a new capability for power gas turbine compressors to …
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Development of a geometric model for the study of propagating stall inception based on flow visualization in a linear cascade
… 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 propagation. The …
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A precision blade mechanism for powder recoating in Selective Laser Melting
… equipment, the layer is spread using a moving blade or roller mechanism (the "recoater"). There is still opportunity to optimize the process and understand how powder mechanics influence the layer quality. This thesis focuses on experimental and computational methods to study powder recoating …
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Propeller performance analysis using lifting line theory
… line theory to characterize the propeller blades. The bound circulation on the lifting line is a function of the blade geometry along with the blade velocity (both rotational and axial). Lerbs provided a method to evaluate the circulation for a given set of these conditions. This thesis …
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Small core axial compressors for high efficiency jet aircraft
… in reductions in stage efficiency up to 1.9% for blades designed for high Reynolds number flow. The calculations carried out indicate that blades optimized for this Reynolds number can increase stage efficiency by up to 1.6%. For small core compressors, non-dimensional tip clearances are …
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