scholarly journals The double‐tree method: An O ( n ) unsteady aerodynamic lifting surface method

2020 ◽  
Vol 92 (10) ◽  
pp. 1394-1414
Author(s):  
Bryn Jones ◽  
Peter Dunning ◽  
Alireza Maheri
Keyword(s):  
Unsteady Aerodynamic ◽  
Surface Method ◽  
Lifting Surface ◽  
Tree Method

Optimization of Wind Turbine Blades Using Lifting Surface Method and Genetic Algorithm

2011 ◽  
Author(s):  
Xin Shen ◽  
Xiao-cheng Zhu ◽  
Zhao-hui Du
Keyword(s):  
Genetic Algorithm ◽  
Design Method ◽  
Turbine Blades ◽  
Optimization Method ◽  
Efficient Design ◽  
Wind Turbine Blades ◽  
Surface Method ◽  
Lifting Surface ◽  
Horizontal Axis Wind Turbines ◽  
Wake Model

This paper describes an optimization method for the design of horizontal axis wind turbines using the lifting surface method as the performance prediction model and a genetic algorithm for optimization. The aerodynamic code for the design method is based on the lifting surface method with a prescribed wake model for the description of the wake. A micro genetic algorithm handles the decision variables of the optimization problem such as the chord and twist distribution of the blade. The scope of the optimization method is to achieve the best trade off of the following objectives: maximum of annual energy production and minimum of blade loads including thrust and blade rood flap-wise moment. To illustrate how the optimization of the blade is carried out the procedure is applied to NREL Phase VI rotor. The result shows the optimization model can provide a more efficient design.

Iterative Lifting Surface Method for Thick Bladed Hovering Helicopter Rotors

1981 ◽  
Vol 18 (6) ◽  
pp. 417-424 ◽  
Author(s):  
K. Rajarama Shenoy ◽  
Robin B. Gray
Keyword(s):  
Helicopter Rotors ◽  
Surface Method ◽  
Lifting Surface

Induced Drag Calculation by Numerical Lifting Surface Method

1997 ◽  
Vol 34 (2) ◽  
pp. 257-259
Author(s):  
Masami Ichikawa ◽  
Akira Matsuda
Keyword(s):  
Induced Drag ◽  
Surface Method ◽  
Lifting Surface

The Myth of the High-Order-Lifting-Surface Method

2005 ◽  
Vol 42 (2) ◽  
pp. 575-575 ◽  
Author(s):  
William P. Rodden
Keyword(s):  
High Order ◽  
Surface Method ◽  
Lifting Surface

Predictions of Fan Broadband Noise Using Lifting Surface Method

AIAA Journal ◽  
2015 ◽  
Vol 53 (10) ◽  
pp. 2845-2855 ◽  
Author(s):  
Weiguang Zhang ◽  
Xiaoyu Wang ◽  
Xiaofeng Sun
Keyword(s):  
Broadband Noise ◽  
Surface Method ◽  
Lifting Surface

A practical technique for improvement of open water propeller performance

2011 ◽  
Vol 225 (4) ◽  
pp. 375-386 ◽  
Author(s):  
S Bal
Keyword(s):  
Vortex Lattice ◽  
Open Water ◽  
Equation System ◽  
Horseshoe Vortex ◽  
Vortex Lines ◽  
Surface Method ◽  
Lifting Surface ◽  
Circulation Distribution ◽  
Propeller Performance ◽  
Lifting Line

A practical technique for the improvement of open water propeller performance has been described by using a vortex lattice lifting line method together with a lifting surface method. First, the optimum circulation distribution, giving the maximum thrust–torque ratio, has been computed along the radius of the propeller for given thrust and chord lengths, by adopting a vortex lattice solution to the lifting line problem. Then, by using the lifting surface method, the blade sectional properties such as pitch-to-diameter ratio and camber ratio, have been calculated for obtaining the desired circulation distribution. The effects of skew and rake on propeller performance have been ignored. The blades have been discretized by a number of panels extending from hub to tip. The radial distribution of bound circulation can be computed by a set of vortex elements having constant strengths. Discrete trailing free vortex lines are shed at each panel boundary, and their strengths are equal to the differences in strength of the adjacent bound vortices. The vortex system has been built from a set of horseshoe vortex elements, and they consist of a bound vortex segment and two free vortex lines of constant strengths. Each set of horseshoe vortex elements induces an axial and tangential velocity at a specified control point on the blades. An algebraic equation system can be formed by using the influencial coefficients. Once this equation system has been solved for unknown vortex strengths and specified thrust, the optimum circulation distribution and the forces can be computed by using Betz–Lerbs method. When the radial distributions of optimum circulation (loading) and chord lengths have been reached, the lifting surface method can be applied to determine the blade pitch and camber distribution. DTMB 4119 and DTMB 4381 propellers have been adopted for calculations and their hydrodynamic characteristics have been found in their open literature. A very good comparison has been obtained between the results of this practical technique and the experimental measurements.

Refinement of the nonplanar aspects of the subsonic doublet-lattice lifting surface method.

1972 ◽  
Vol 9 (1) ◽  
pp. 69-73 ◽  
Author(s):  
W. P. RODDEN ◽  
J. P. GIESING ◽  
T. P. KALMAN
Keyword(s):  
Surface Method ◽  
Lifting Surface
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