Effect of Wake Alignment on Turbine Blade Loading Distribution and Power Coefficient

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
David H. Menéndez Arán ◽  
Ye Tian ◽  
Spyros A. Kinnas
Keyword(s):  
Optimization Method ◽  
Power Coefficient ◽  
Viscous Drag ◽  
Lattice Method ◽  
Blade Loading ◽  
Vortex Lattice Method ◽  
Abrupt Changes ◽  
Alignment Model ◽  
Wake Alignment ◽  
Lifting Line

This paper describes the use of a lifting line model in order to determine the optimum loading on a marine turbine's blades. The influence of the wake and its geometry is represented though the use of a full wake alignment model. The effects of viscous drag are included through a drag-to-lift ratio. Results for different number of blades and tip speed ratios are presented. Various types of constraints are imposed in the optimization method in order to avoid abrupt changes in the designed blade shape. The effect of the constraints on the power coefficients of the turbines is studied. Once the optimum loading has been determined, the blade geometry is generated for a given chord and camber distributions. Finally, a vortex-lattice method is used to verify the power coefficient of the designed turbines.

Computational Models for Prediction of Performance and Design of Tidal Turbines

2010 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Wei Xu ◽  
Yi-Hsiang Yu
Keyword(s):  
Computational Models ◽  
Vortex Lattice ◽  
Design Procedure ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Tidal Turbines ◽  
Unsteady Wake ◽  
Tidal Turbine ◽  
Wake Alignment ◽  
Lifting Line

In this paper, the performance of a horizontal axis, 3-blade tidal turbine is predicted by a vortex lattice method, in which the fully unsteady wake alignment is utilized to model the trailing wake geometry. A blade design procedure, which combines a lifting line approach with the vortex lattice analysis method and a nonlinear optimization scheme, is proposed.

On Fully Aligned Lifting Line Model for Propellers: An Assessment of Betz condition

2014 ◽  
Vol 58 (03) ◽  
pp. 130-145
Author(s):  
David H. Menéndez Arán ◽  
Spyros A. Kinnas
Keyword(s):  
Image Model ◽  
Numerical Accuracy ◽  
Line Model ◽  
Alignment Model ◽  
Wake Alignment ◽  
Lifting Line

We discuss the optimum propeller loading through the use of a lifting line model. Viscous terms are included through a drag-to-lift ratio, and a hub image model is implemented. Two types of trailing wake geometries are considered: one based on helical wakes, which are aligned at the blade (using the so-called "moderately loaded propeller" assumption), and a second one based on a full wake alignment model to represent more accurately the wake geometry and its effect on the efficiency of the propeller. A comparison of the efficiencies and the loading distributions obtained through both methods is presented as well as convergence and numerical accuracy studies. The accuracy of Betz condition according to both wake models is tested, and conclusions are drawn based on these results.

Unsteady aerodynamics investigation of deploying tandem-wing with different methods

2018 ◽  
Vol 233 (10) ◽  
pp. 3714-3733 ◽  
Author(s):  
Hao Cheng ◽  
Hua Wang ◽  
Qingli Shi ◽  
Mengying Zhang
Keyword(s):  
Fore Wing ◽  
Vortex Lattice ◽  
Lift Coefficient ◽  
Unsteady Aerodynamics ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Induced Drag ◽  
Lifting Line ◽  
Lifting Line Method ◽  
Unsteady Lift

In the rapidly deploying process of the unmanned aerial vehicle with folding wings, the aerodynamic characteristics could be largely different owing to the effects of deformation rate and the aerodynamic interference. The investigation on the unsteady aerodynamics is of great significance for the stability analysis and control design. The lifting-line method and the vortex-lattice method are improved to calculate the unsteady aerodynamics in the morphing stage. It is validated that the vortex-lattice method predicts the unsteady lift coefficient more appropriately than the lifting-line method. Different tandem wing configurations with deployable wings are simulated with different deformation rates during the morphing stage by the vortex-lattice method. As results indicated, the unsteady lift coefficient and the induced drag of the fore wing rise with the deformation rate increasing, but it is reversed for the hind wing. Additionally, the unsteady lift coefficient of the tandem wing configuration performs well with a larger stagger, a larger magnitude of the gap and a larger wingspan of the fore wing; however, the total induced drag has a larger value for the configuration that the two lifting surfaces with the same wingspans are closer to each other.

scholarly journals Forward flight of birds revisited. Part 1: aerodynamics and performance

2014 ◽  
Vol 1 (2) ◽  
pp. 140248 ◽  
Author(s):  
G. Iosilevskii
Keyword(s):  
Flight Performance ◽  
Lattice Method ◽  
Method Performance ◽  
Entire Study ◽  
Vortex Lattice Method ◽  
Aerodynamic Model ◽  
High Speeds ◽  
The Difference ◽  
And Performance ◽  
Lifting Line

This paper is the first part of the two-part exposition, addressing performance and dynamic stability of birds. The aerodynamic model underlying the entire study is presented in this part. It exploits the simplicity of the lifting line approximation to furnish the forces and moments acting on a single wing in closed analytical forms. The accuracy of the model is corroborated by comparison with numerical simulations based on the vortex lattice method. Performance is studied both in tethered (as on a sting in a wind tunnel) and in free flights. Wing twist is identified as the main parameter affecting the flight performance—at high speeds, it improves efficiency, the rate of climb and the maximal level speed; at low speeds, it allows flying slower. It is demonstrated that, under most circumstances, the difference in performance between tethered and free flights is small.

scholarly journals METHODOLOGY FOR ASSESSMENT OF THE WEIGHT CHARACTERISTICS OF THE CARGO AIRCRAFT WINGS USING MULTIDISCIPLINARY NUMERICAL SIMULATION AND ANALYTICAL METHODS OF MULTI OBJECTIVE OPTIMIZATION

2020 ◽  
Vol 22 (5) ◽  
pp. 120-127
Author(s):  
O.U. Espinosa Barcenas ◽  
◽  
O.E. Lukyanov ◽  
Keyword(s):  
Mathematical Modeling ◽  
Load Distribution ◽  
Optimization Method ◽  
Load Factor ◽  
Multi Objective Optimization ◽  
The Finite Element Method ◽  
Lattice Method ◽  
Aircraft Wings ◽  
Vortex Lattice Method ◽  
Multi Objective

The developed methodology determines the weight characteristics of a wing of high aspect ratio using the integral criterion - the carrying load factor coefficient and numerical mathematical modeling in the fields of aerodynamics and rigid body mechanics. The paper considers the application of a multi-objective optimization method based on genetic algorithms to find the rational position of the spars in the wing when choosing its structural scheme. The calculation of the air load distribution within the framework of the proposed method is based on mathematical modeling of flows by the vortex lattice method. The ideal weight criterion is calculated based on the stress state of the wing structure obtained by the finite element method. The efficiency of the method is shown by the example of solving a demonstration problem to assess the influence of several geometric parameters of the wing on the air load distribution and its weight characteristics.

A Combined Vortex Lattice Lifting Line Method for Unsteady Propeller Calculations

2021 ◽  
Author(s):  
Andreas Büsken ◽  
Stefan Krüger
Keyword(s):  
Vortex Lattice ◽  
Suction Side ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Vortex Model ◽  
Coupling Strategy ◽  
Line Theory ◽  
Lifting Line ◽  
Oseen Vortex ◽  
Lifting Line Method

Abstract This paper presents a Combined Method for the calculation of propeller forces in inhomogeneous inflow. It consists of an extended Goldstein approach based on Lifting Line Theory and a Vortex Lattice Method. After a brief overview of both methods is given, the coupling strategy is described and the additional modifications are explained. A correction factor accounting for the vortex which develops under a separated and later reattached flow on the suction side of the propeller blade is implemented as the first modification. Further, the Lamb-Oseen vortex model is used for the vortices in the free vortex system of the propeller. Finally, some results achieved with the described method are presented and compared to measured values.

Generalized vortex lattice method for planar supersonic flow

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1230-1233
Author(s):  
Paulo A. O. Soviero ◽  
Hugo B. Resende
Keyword(s):  
Supersonic Flow ◽  
Vortex Lattice ◽  
Lattice Method ◽  
Vortex Lattice Method

scholarly journals Static Aeroelastic Characteristics of Morphing Trailing-Edge Wing Using Geometrically Exact Vortex Lattice Method

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Sen Mao ◽  
Changchuan Xie ◽  
Lan Yang ◽  
Chao Yang
Keyword(s):  
Vortex Lattice ◽  
Deflection Angle ◽  
Aircraft Design ◽  
Analysis Method ◽  
Lattice Method ◽  
Trailing Edge ◽  
Vortex Lattice Method ◽  
Analysis And Design ◽  
Aeroelastic Analysis ◽  
Typical Model

A morphing trailing-edge (TE) wing is an important morphing mode in aircraft design. In order to explore the static aeroelastic characteristics of a morphing TE wing, an efficient and feasible method for static aeroelastic analysis has been developed in this paper. A geometrically exact vortex lattice method (VLM) is applied to calculate the aerodynamic forces. Firstly, a typical model of a morphing TE wing is chosen and built which has an active morphing trailing edge driven by a piezoelectric patch. Then, the paper carries out the static aeroelastic analysis of the morphing TE wing and corresponding simulations were carried out. Finally, the analysis results are compared with those of a traditional wing with a rigid trailing edge using the traditional linearized VLM. The results indicate that the geometrically exact VLM can better describe the aerodynamic nonlinearity of a morphing TE wing in consideration of geometrical deformation in aeroelastic analysis. Moreover, out of consideration of the angle of attack, the deflection angle of the trailing edge, among others, the wing system does not show divergence but bifurcation. Consequently, the aeroelastic analysis method proposed in this paper is more applicable to the analysis and design of a morphing TE wing.

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