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 62 for “"lift coefficient"”.
-
An Approximate Numerical Method for the Optimization of Flap Design for Maximum Lift Coefficient
Made available in DSpace on 2014-12-14T04:42:00Z (GMT). No. of bitstreams: 1 7524297.pdf: 4657836 bytes, checksum: efb3249ae596e00155e4ccd68a6957ff (MD5) Previous issue date: 1975
-
The Determination of The Geometries of Multiple-Element Airfoils Optimized for Maximum Lift Coefficient
Made available in DSpace on 2014-12-10T23:36:42Z (GMT). No. of bitstreams: 1 7219807.pdf: 2949668 bytes, checksum: 3b33180f3c2446062c683a8a215da291 (MD5) Previous issue date: 1972
-
Lift on a sphere in shear flow near flat channel bed
The lift and drag forces exerting on a sphere immersed in a shear flow above a flat channel bed are evaluated by solving the steady three-dimensional Navier-Stokes equations. The numerical technique which combines the Newton iteration method and the finite element method is used to solve the …
-
3D Dynamic Stall Simulation of Flow over NACA0012 Airfoil at 10⁵ and 10⁶ Reynolds Numbers
… Smagorinsky model at the sub grid scale. The lift hysteresis plots of this simulation for both the configurations are compared with the corresponding experiments. The development of dynamic stall vortex, vortex shedding and reattachment as predicted by the present study are discussed in …
-
Active Flow Control of a Three-Element Airfoil in Unbounded Flow and in Ground Effect
<p>Multi-element high lift devices are used in aircraft wings to have higher lift at low speed during take-off and landing. 30P30N is a three-element airfoil developed by NASA/McDonnell Douglas for which high quality flow field data is available. As a result, it has been a subject of many …
-
Simulation of vortex induced vibration of a bluff body structure
… the turbulent flow to evaluate the drag and lift coefficient of circular towards the flow characteristics which used time independent test (transient) and tested at different Reynolds number between 10000 and 100000 with uniform velocities of 1.35m/s and 13.5m/s. Results from dynamic response …
-
Vortex-induced vibration of marine risers : motion and force reconstruction from field and experimental data
… modeling of riser VIV by extracting empirical lift coefficient databases from field riser VIV measurements. The existing experiment-based lift coefficient databases are represented in a flexible parameterized form using a set of carefully chosen parameters. Extraction of the lift coefficient …
-
The Influence of Propeller Position and Size on the Aerodynamics of Blown Wings
… edge, each powering a propeller, increased lift can be achieved by blowing high velocity jets over the wing. This allows the wing to be reduced in size, decreasing its cruise drag, whist still maintaining the same lift during take-off and landing. It is shown that the use of small diameter …
-
Flow Separation Control Using Synthetic Jets on a Flat Plate
… thereby providing significant increase in the lift coefficient.</p> <p>The performed numerical simulation investigates the flow at Re = 2×10^6. The oscillatory injection takes place at one fourth the length of the chord from the leading edge. Streamline fields and the pressure contours obtained …
-
The Investigation of an Inboard-Winglet Application to a Roadable Aircraft
… its flow characteristics by testing for pressure coefficients over the wing and winglet surface in the Virginia Tech Stability Wind Tunnel over a range of freestream velocity and angle of attack. The results were analytically applied to calculate aircraft performance of a roadable aircraft, …
-
Clean Wing Airframe Noise Modeling for Multidisciplinary Design and Optimization
… wing airframe noise such as the aircraft speed, lift coefficient, and wing geometry. It can also capture three-dimensional effects which become important at high lift coefficients, since the characteristic velocity and the length scales are allowed to vary along the span of the wing. Noise metric …
-
The turbulence structure of trailing vortex wakes
… were made for a range of Reynolds numbers and lift coefficients. These visualizations reveal the near-instantaneous turbulence structure of the wing wake which is dominated by a vortex pair and a connecting "braid" wake. The braid spacing decreases with increasing Reynolds number and is …
-
Development of Reduced-Order Models for Lift and Drag on Oscillating Cylinders with Higher-Order Spectral Moments
… the development of reduced-order models for the lift and drag on oscillating cylinders and the identification of their parameters. Amplitudes and phases of higher-order spectral moments of the lift and drag coefficients data are combined with approximate solutions of the representative models to …
-
Computational and Experimental Study on Vertical Axis Wind Turbine in Search for an Efficient Design
… roughness effect, relatively high drag and low lift coefficient. Integration of Computational Fluid Dynamics (CFD) simulation and wind tunnel experimentation has made the current research more acceptable. 3-Dimensional CAD models of various simple airfoils have been designed in Solidworks. Using …
-
Time-Resolved Analysis of Circulation Control over Supercritical Airfoil using Digital Particle Image Velocimetry (DPIV)
… have shown noteworthy improvements in lift compared to traditional means. The General Aviation Circulation Control (GACC) concept currently under investigation at NASA's Langley Research Center (LaRC) is an attempt at addressing some of the fundamental obstacles related to the …
-
Aerodynamic pitch-up of cranked arrow wings: estimation, trim, and configuration design
… drag without suffering greatly from low lift/drag ratios in low-speed flight. They can, however, suffer from pitch-up at modest angles of attack (as low as 5°) during low-speed flight due to leading edge vortex influence, flow separation and vortex breakdown. The work presented here …
-
A Study of Spherical Bubbles in a Vertical Turbulent Boundary Layer
… Analysis of the force results indicate that drag coefficient decreases with increasing Reynolds number, but decreases with increased turbulence intensity. The lift coefficient is much higher than creeping flow or inviscid theory and tends to decrease with increasing bubble Reynolds number.
-
Improved turbulent lift momentum closure for multiphase computational fluid dynamics
… transfer between phases, the interfacial lift force strongly affects the lateral migration of the gas phase in bubbly flow, which strongly impacts the predictions of pressure drop and heat transfer [2]. Recent work from Sugrue has proposed an improved physical representation of the …
-
Unsteady modes in the flowfield about an airfoil with a leading-edge horn-ice shape
… in the spectral content of the iced-airfoil lift coefficient. The resulting values of Strouhal number exhibited a dependence on the airfoil angle of attack and corresponded to a range that was consistent with the Strouhal number values reported in prior studies of the low-frequency mode in …
-
Study of Contra-Rotating Coaxial Rotors in Hover: A Performance Model Based on Blade Element Theory Including Swirl Velocity
… blade chord, and airfoil's shape through its lift coefficient versus angle of attack slope. Different blade pitch distributions are tried and are assessed based on the power required to hover at the same weight. Also, the impact of the swirl velocity induced by the upper rotor is included and …
Page 1 of 4