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Showing 1 to 13 of 13 for “"Laminar--Turbulent Transition"”.
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LAMINAR TURBULENT TRANSITION - SPECTRAL ANALYSIS AND COHERENT STRUCTURES OF DNS WAVEPACKETS
… simulation (DNS) of wavepackets undergoing laminar turbulent transition in a Blasius boundary layer. A fully crossed factorial simulation design is used, in which 18 different wavepackets are analyzed to determine the combined effects of frequency, bandwidth and amplitude on the transition …
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Investigation of the Laminar-Turbulent Transition Process in Steady and Periodic Tube Flow (With Special Consideration to the Experimental Evaluation of Proposed Transition Criteria)
Made available in DSpace on 2014-12-09T17:13:34Z (GMT). No. of bitstreams: 1 6503703.pdf: 4169441 bytes, checksum: ddf318087fdced049f8da6224090a56e (MD5) Previous issue date: 1964
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Transitional and turbulent flow of non-Newtonian slurries in pipes
… systems conveying non-Newtonian slurries in the turbulent flow regime has been large scale-pipe-tests. This thesis addresses this design problem, with particular emphasis on the theoretical modelling of the laminar/turbulent transition and turbulent flow behaviour of these slurries in pipes. The …
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Design and Analysis of Low Reynolds Number Marine Propellers with Computational Fluid Dynamics (CFD) Transition Modeling
… operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of the boundary layer, …
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The rheological characterisation of non- Newtonian slurries using a novel balanced beam tube viscometer
… of the data obtained using the BBTV in both the laminar and turbulent flow regimes. (iii) Comparison with the rotary type viscometer. Kaolin clay and uranium tailings slimes slurries of different particle size range and concentration have been successfully characterised by yield- pseudoplastic …
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Computational Assessment of Flow through a High-Flow Nacelle Bypass for Low Supersonic Boom
… turbulence model on predictive accuracy due to a laminar-turbulent transition affecting the inflow velocity profile.
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Characterization and mitigation of blade waviness effects on fan performance
… performance is characterized. The mechanisms for laminar-turbulent transition are assessed numerically and experimentally over relevant range of aerodynamic and geometric parameters. The governing mechanism (natural transition triggered by receptivity amplification from surface waviness) is …
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Machine Learning Approaches to Data-Driven Transition Modeling
Laminar-turbulent transition has a strong impact on aerodynamic performance in many practical applications. Hence, there is a practical need for developing reliable and efficient transition prediction models, which form a critical element of the CFD process for aerospace vehicles across multiple …
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Numerical Simulation of Flows past a Circular and a Square Cylinder at High Reynolds Number, and a Curved Plate in Transitional Flow
… of a one-equation model. Another case of transitional flow past a circular arc is simulated in this thesis. For this case it has been found experimentally that a sharp and sudden increase in lift and decrease in drag occurs at a certain Reynolds number (called the lift and drag crisis). …
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Aerodynamic and Acoustic Modeling for eVTOL Rotor Noise Prediction
… low-Reynolds-number flow physics, including laminar-turbulent transition and laminar separation bubble behavior.</p> <p>Predicted acoustic spectra were validated against experimental measurements obtained in the Virginia Tech Stability Wind Tunnel. Results demonstrate that turbulence model …
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Quantification of Reynolds-averaged-Navier-Stokes Model Structural Hypothesis Uncertainty in Transitional Boundary Layer and Airfoil Flows
The Boussinesq turbulent-viscosity hypothesis is intrinsic to many Reynolds-averaged-Navier-Stokes (RANS)-based turbulence models and transition models. Although its drawback has been well acknowledged, the uncertainty it induces on RANS predictions of transitional flows has been ignored so far due …
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Spatial-temporal patterns in evolutionary ecology and fluid turbulence
… and the ecology of turbulence. Ecosystems and turbulent fluids are both highly non-equilibrium and exhibit spatio-temporal complexity during the course of their evolution. It might seem that they are too complicated to extract universal properties, even if there are any. Surprisingly, it turns …
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Transport of Heat and Momentum In Non-Equilibrium Wall-Bounded Flows
… to better understand the underlying physics, transition dynamics, and appropriate flow scaling in non-equilibrium flows. Non-equilibrium flows, in which the mean flow time scales are comparable to turbulent flow time scales, do not exhibit universal behaviors and cannot be characterized only …