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 “"Total pressure distortion"”.
-
Design of a Total Pressure Distortion Generator for Aircraft Engine Testing
… during the creation and propagation of the distortion. Total pressure distortions occur in gas turbine engines when the incoming flow is disturbed. Dynamic total pressure changes may happen slowly, or may occur very rapidly. The disturbance of the incoming flow can change engine operating …
-
Full Scale Experimental Transonic Fan Interaction with a Boundary Layer Ingesting Total Pressure Distortion
… between a full scale transonic fan and a total pressure distortion representative of a boundary layer ingesting serpentine inlet. A five-hole pneumatic probe was traversed directly in front of and behind a fan rotor to fully characterize the inlet and outlet fan profile. The distortion …
-
The Influence of Development and Fan/Screen Interaction on Screen-Generated Total Pressure Distortion Profiles
… interest in fan performance in the presence of total pressure distortion, a topic of fundamental interest for integrated airframe/engine architectures, has led to increased research in ground based testing environments. Included in these studies is the generation of simulated total pressure …
-
One-Dimensional Dynamic Wake Response in an Isolated Rotor due to Inlet Total Pressure Distortion
… with and without the presence of steady inlet total pressure distortions. The steady three-dimensional rotor inlet flow was obtained by a five-hole pneumatic pressure probe, while the one-dimensional rotor exit data were obtained using a piggyback steady/unsteady total pressure probe in …
-
Effect of a sinusoidal three-lobe total pressure distortion on a transonic compressor : distortion propagation, compressor performance, and blade passage events
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, June 2003.
-
Use of Nonlinear Volterra Theory in Predicting the Propagation of Non-uniform Flow Through an Axial Compressor
Total pressure non-uniformities in an axial flow compressor can contribute to losses in aerodynamic operability through a reduction in stall margin, pressure rise and mass flow, and to loss of structural integrity through means of high cycle fatigue (HCF). HCF is a primary mechanism of blade …
-
Prediction of Inlet Distortion Transfer Through the Blade Rows in a Transonic Axial Compressor
Inlet total pressure non-uniformities in axial flow fans and compressors can contribute to the loss of component structural integrity through high cycle fatigue (HCF) induced by the excitation of blade vibratory modes. As previous research has shown total pressure distortion to be the dominant HCF …
-
Frequency Domain Methods for Predicting the Transport of Non-Uniform Flow Through Turbomachinery Compressors
… method to predict the transport of non-uniform total pressure distributions through an axial flow compressor is presented. The method relies on frequency-domain transformations of total pressure distortion patterns, and the use of digital filter techniques to capture the effect of a blade row on …
-
Measurement and Uncertainty Analysis of Transonic Fan Response to Total Pressure Inlet Distortion
Distortion tolerant fans represent the enabling technology for the successful implementation of highly integrated airframe propulsion system vehicles. This investigation extends the study of fan-distortion interactions to an actual turbofan engine with a total pressure distortion profile …
-
Modal Response of a Transonic Fan Blade to Periodic Inlet Pressure Distortion
… predicting forced vibratory blade response to total pressure distortion has been developed using modal and harmonic analysis. Total pressure distortions occur in gas turbine engines when the incoming airflow is partially blocked or disturbed. Distorted inlet conditions can have varying effects …
-
Non-Intrusive Sensing and Feedback Control of Serpentine Inlet Flow Distortion
A technique to infer circumferential total pressure distortion intensity found in serpentine inlet airflow was established using wall-pressure fluctuation measurements. This sensing technique was experimentally developed for aircraft with serpentine inlets in a symmetric, level flight condition. …
-
Effectiveness of a Serpentine Inlet Duct Flow Control Scheme at Design and Off-Design Simulated Flight Conditions
… for several simulated flight conditions. The total pressure distortion at the aerodynamic interface plane (AIP) was then used to predict the resulting stability for a compression system. This study was conducted using a model of a compact, low observable, engine inlet duct developed by …
-
Effect of BLI-Type Inlet Distortion on Turbofan Engine Performance
… of the effects of this specific type of inlet distortion on engine performance in the form of numerical simulations. This work seeks to provide an experimental analysis of the effects of BLI-type distortion on a turbofan engine's performance. A modified JT15D-1 turbofan engine was investigated …
-
Study of Steady-State Wake Characteristics of Variable Angle Wedges
Current methods of creating inlet total pressure distortion for testing in gas turbine engines are only able to simulate steady-state distortion patterns. With modern military aircraft it is becoming necessary to examine the effects of transient inlet distortion on engines. One alternative being …
-
Stereoscopic Particle Image Velocimetry Measurements of Swirl Distortion on a Full-Scale Turbofan Engine Inlet
… for simulation and measuring the inlet swirl distortion generated by airframe/engine system interactions to identify potential degradation in fan performance and operability in a full-scale, ground testing environment. Efforts are described to address this need by developing and characterizing …
-
Active control of rotating stall in a transonic compressor stage with inlet distortion
… transonic axial flow compressor with inlet distortion using active feedback control. The experiments were conducted at the NASA Lewis Research Center on a single-stage transonic core compressor. An annular array of 12 jet-injectors located upstream of the rotor tip was used for forced …
-
Hybrid wing-body aircraft noise and performance assessment
… gear and elevons on approach. A lower fan pressure ratio and advanced landing gear fairings are recommended to decrease N2A overall noise levels. The available engine noise estimation tools were inadequate to model the N2B distributed propulsion system and rectangular exhaust nozzle; …
-
Installation Effects on Variable Pitch Fans
Future low pressure ratio fan systems require an extended operating range and variable pitch fans can achieve this by re-pitching the rotor blades. Moreover, a variable pitch fan has the potential of reducing fuel burn if sufficient reverse thrust can be generated, such that the engine weight and …