Comparative analysis of the analytical methods and numerical modeling for the lift force of a WIG craft’s wing

The paper analyzes the methods and formulas for calculating the lift force coefficient Сy of a simple wing with washers from the point of view of the possibility of using it in preliminary design of wing-in-ground-effect crafts. 5 methods were identified that allow calculating the increase in the lift force coefficient from the action of the ground effect. Adequacy was checked by comparing the calculation results for each of the methods with the experimental data of the blowing of 3 variants of the wings in wind tunnels with washers at different aspect ratio, angles of attack and flight altitudes for the TsAGI-876 profile. Also done a numerical simulation of the flow around a rectangular wing with washers with various geometric and hydrodynamic characteristics was carried out. The analysis of the calculated, experimental and numerical results showed that the most expedient use in preliminary design P. A. Amplitov and the method of J. D. Anderson methods. At the same time, one of them is also capable of determining the values of the lift force coefficient in the zone of supercritical angles of attack with an error not exceeding 4-8% for cruising angles of attack of the wing of wing-in-ground-effect crafts.

Aeroelastic Analysis of a Single Element Composite Wing in Ground Effect Using Fluid Structure Interaction

The present work focuses on an advanced coupling of computational fluid dynamics (CFD) and structural analysis (FEA) on the aeroelastic behaviour of a single element inverted composite wing with the novelty of including the ground effect. The front wing of the Formula One (F1) car can become flexible under the fluid loading due to elastic characteristics of composite materials, resulting in changing the flow field and eventually altering overall aerodynamics. The purpose of this study is to setup an accurate fluid-structure interaction (FSI) modelling framework and to assess the influence of elastic behaviour of the wing in ground effect on the aerodynamic and structural performance. Different turbulence models are studied to better capture the changes of the flow field and variation of ride heights are considered to investigate the influence of ground effect on aerodynamic phenomena. A steady-state two-way coupling method is exploited to run the FSI numerical simulations using ANSYS, which enables simultaneous calculation by coupling CFD with FEA. The effect of various composite structures on the wing performance is extensively studied concerning structure configuration, ply orientation and core materials. The numerical results generally represent good agreement with the experimental data, however, discrepancy, especially in the aerodynamic force, is presented. This may be consequence of less effective angle of attack due to the wing deflection and deterioration of vortex-induced effect. For the structural analysis, the woven structure gives rise to more stable structural deflection than the unidirectional structure despite the associated weight penalty.

Оценка аэродинамических и летно-технических характеристик экраноплана с учетом поддува струи от воздушного винта

Аннотация: Представлены основные результаты исследования (с использованием CFD-технологий и упрощенной авторской методики) аэродинамических характеристик экраноплана схемы «тандем» с учетом поддува и влияния струи от движителя – воздушного винта. Вычислительный эксперимент производился в программе ANSYS. Его условия предусматривали изменение кинематических параметров полета и положения экраноплана относительно экрана, скорости и угла выдува струи, углов отклонения рулевых поверхностей и элементов механизации. Анализ результатов позволяет сделать выводы об эффективности применения поддува к данной компоновочной схеме экраноплана, а также выявить основные особенности изменения ее аэродинамических характеристик при различных параметрах струи, конфигурации и положения экраноплана относительно экрана. Также рассмотрены некоторые особенности летно-технических характеристик экраноплана с учетом влияния струй от воздушного винта. Результаты работы могут быть использованы при проектировании экранопланов. Ключевые слова: экраноплан, аэродинамика экраноплана, аэродинамический поддув, динамическая воздушная подушка This paper presents the primary results of the study of the aerodynamic characteristics of a WIG, with due consideration of the blow and the influence of jets from the propeller, using CFD technologies. WIG of the Tandem scheme is considered as the object of this research. The paper presents a simplified technique for modeling a jet from a propeller. The computational experiment for the study of aerodynamic characteristics was carried out in the ANSYS finite element analysis program. The conditions of the computational experiment provided for changing the kinematic parameters (position of the WIG against the screen), speed of the jet, the angle of the jet blow, and use of wing mechanization (flaps). Analysis of the results leads to conclusions on effectiveness of the blowing application to this layout of the WIG. It also allows to reveal major effects from changing its aerodynamic characteristics with various jet parameters, configuration and position of the WIG against the ground. The paper also considers some of the features of WIG flight performance taking into account the effect of jets from the propeller. Keywords: PAR (Power-augmented Ram), GEV (ground-effect vehicle), WIG (wing-in-ground-effect)

Design of Unmanned Wing-in-ground Effect Vehicle with Tri-fold Main Wing

This paper proposed an innovative design of unmanned wing-in-ground effect vehicle with tri-fold main wing, aiming at optimizing the main wing of unmanned vehicles based on its current application. The design also takes into account the speed and load in an effort to improve efficiency and broaden the application of the vehicle. In addition, the unmanned GEV is driven by electric power and propelled by the main and auxiliary propellers, which is well supported by the ground effect. The design features energy conservation and emission reduction, which is worthy of promoting in the market.

The Effect of Cornering on the Aerodynamics of a Multi-Element Wing in Ground Effect

This research investigates the effects of cornering on a multi-element wing in ground effect with the aim to improve the understanding of such in the effort to improve the performance of open-wheel race cars. A numerical validation study was performed to confirm the validity of the Detached Eddy Simulation CFD methodology used. This involved comparing numerical data with wind tunnel experimental data using a force balance and PIV for the velocity field to reveal the trajectory of the trailing vortex system. Once validated, the CFD was used to test the wing within a cornering condition as well as fixed yaw condition and its aerodynamic performance relative to the straight-line condition was analysed. Asymmetry was the general theme concerning the on-surface pressure distribution with this most prominent under the cornering condition. Ultimately, minimal change was observed regarding the downforce generated whilst drag was found to increase in the cornering condition and decrease slightly in the fixed yaw condition. Asymmetry was also observed in the wake of the wing where alterations to the relative strengths of the vortices was observed as well as their downstream paths which was generally governed by the direction of the freestream flow.