Vortex lattice method

About: Vortex lattice method is a research topic. Over the lifetime, 779 publications have been published within this topic receiving 9242 citations.

Static Aeroelastic Scaling and Analysis of a Sub-Scale Flexible Wing Wind Tunnel Model

Abstract: This paper presents an approach to the development of a scaled wind tunnel model for static aeroelastic similarity with a full-scale wing model The full-scale aircraft model is based on the NASA Generic Transport Model (GTM) with flexible wing structures referred to as the Elastically Shaped Aircraft Concept (ESAC) The baseline stiffness of the ESAC wing represents a conventionally stiff wing model Static aeroelastic scaling is conducted on the stiff wing configuration to develop the wind tunnel model, but additional tailoring is also conducted such that the wind tunnel model achieves a 10% wing tip deflection at the wind tunnel test condition An aeroelastic scaling procedure and analysis is conducted, and a sub-scale flexible wind tunnel model based on the full-scale's undeformed jig-shape is developed Optimization of the flexible wind tunnel model's undeflected twist along the span, or pre-twist or wash-out, is then conducted for the design test condition The resulting wind tunnel model is an aeroelastic model designed for the wind tunnel test condition

Aerodynamic Analysis and Optimization of Airfoils Using Vortex Lattice Method

Abstract: Air transport is one of the fastest means of transport in the modern world. Aircraft’s efficiency depends on the efficiency of its subparts and its subsystems individually. For example, the gas turbine used as main source of thrust in aircrafts has to be largely efficient, which adds to the overall efficiency of the aircraft. The same way, another important part of the aircraft is the wing. Wings are the main reason for an air vehicle to fly. Aerodynamic parameters like lift, drag and the ratio of co-efficient of lift to drag which is CL/CD ratio determines the efficiency of the aircraft wing. This CL/CD ratio depends on the cross section of the wing, i.e. the airfoil. This paper emphasizes aerodynamic analysis on airfoils NACA 0018, NACA 2412, NACA 4412, USA 45, TSAGI-S12 and B737A used on different planforms of an aircraft wing like Rectangular, Elliptical, Delta and Swept back wing. The results are analyzed and the best airfoil corresponding wing shape is reported. This best airfoil is further refined effectively to get high CL/CD ratio. The complete analysis and airfoil optimization were carried on XFLR5 software which is governed by Naiver-Stokes equations. The airfoils were analyzed for a velocity of 50 m/s, at an angle of attack of 7°, up to a maximum Re (Reynolds Number) of 3e+06, the wing chord length at root, CR=1m and total wing span, L=10m was kept constant throughout the analysis for uniformity. Post analysis, the best three airfoils were further interpolated and refined to obtain higher CL/CD ratio.

Fluid-Structure Interaction Analysis of Hingeless Rotor Blades in Hover Considering Wake Effects

Abstract: Aeroelastic analysis of hingeless rotor blades in hover was performed. Large deflection beam theory was applied to analyze blade motions with effects of geometric structural nonlinearity. Aerodynamic loads for aeroelastic analysis were calculated through a three-dimensional aerodynamic model which is based on the unsteady vortex lattice method. Wake geometry was described using a time-marching free-wake method. Lead-lag damping ratio and frequency were calculated to evaluate aeroelastic stability of hingeless rotor system. Numerical results of aeroelastic analysis for hingeless rotor blades were presented and compared with results based on experimental data and two-dimensional quasi-steady strip theory in which uniform inflow model was used. It was shown that wakes significantly affect the steady-state deflections and aeroelastic stability.

Aeroelastic Shape Optimization of a Pluging Plate

Abstract: In this paper, aeroelastic shape optimization is performed on flapping micro air vehicle (MAV) wings in forward flight. The aeroelastic model tightly couples the structural plate finite element model with an unsteady vortex lattice method aerodynamic model. A gradient-based optimizer is used to maximize the cycle-average thrust generated by the wing while minimizing the power requirements. The multiobjective optimization is performed using the -constraint method. The optimizer creates wings that maximize the span while the chord is limited by the power constraint.