The aerodynamics and flow physics of a NACA 4412 airfoil in ground effect for a wide range of angles of attack from −4 to 20 deg are investigated by numerical simulations. The compressible Reynolds-averaged Navier–Stokes equations and shear-stress transport k-ω turbulence model equations are solved using the finite-volume method. Analyses of the computed results show that the angle of attack versus height (above the ground) plane can be divided into three regions based on the sign of the lift increment value: region I of positive ground effect, and regions II and III of negative ground effect. For low-to-moderate angles of attack, when the ride height is reduced, the airflow is blocked in the convergent passage between the lower surface of the airfoil and the ground, resulting in increase of pressure on the lower surface of the airfoil. As a consequence, the effective angle of attack decreases, and there is less upward deflection of the streamlines, resulting in an increase in pressure on the upper surfac...

Airfoil Aerodynamics in Ground Effect for Wide Range of Angles of Attack

An experimental comparison between different artificial air cavity designs for a planing hull

Hydrodynamic coefficient estimation for ship manoeuvring in shallow water using an optimal truncated LS-SVM

Literature review on evaluation and prediction methods of inland vessel manoeuvrability

http://library.um.ac.id/free-contents/downloadpdf.php/buku/fundamentals-of-aerodynamics-jhon-d-anderson-jr-39369.pdf

Fundamentals of Aerodynamics / Jhon D. Anderson, Jr.

Manoeuvring prediction of pusher barge in deep and shallow water

A mathematical model on manoeuvrability of a LNG tanker in vicinity of bank in restricted water

The performance of a wing-in-ground effect craft depends mostly on its wing configuration. The aerodynamic characteristics of compound wings were numerically investigated during the ground effect. The compound wing was divided into three parts with one rectangular wing in the middle and two reverse taper wings with anhedral angle at the sides. The NACA 6409 airfoil was employed as a section of wings. Three-dimensional computational fluid dynamics was applied as a computational scheme. The k-"turbulent model was used for the turbulent ?ow over wing surface. The computational results of a rectangular wing with aspect ratio 1, angle of attack 2 deg, and different ground clearance were compared with the experimental data of other published work. Next, the principal aerodynamic characters of compound wings and a rectangular wing were computed for various ground clearance. The aerodynamic characters of compound wings were compared with the rectangular wing, which has an acceptable increase in lift and decrease in drag. Consequently, the lift-to-drag ratio has a considerable improvement especially in small ground clearance, although their nose-down pitching moment has a little reduction. The performance of the wing improves noticeably for a certain total span of compound wing when the span of the middle part becomes smaller.

http://www.fkm.utm.my/~azwadi/pdf_publication/ISI8.pdf

Numerical Investigation on Aerodynamic Characteristics of a Compound Wing-in-Ground Effect

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

/pdf/experimental-investigation-of-a-wing-in-ground-effect-craft-lnzcommh5t.pdf

Experimental investigation of a wing-in-ground effect craft.

In this paper, a constraint Genetic Algorithm is used for the purpose of mooring pattern optimization. The Genetic Algorithm is applied through a mathematical formulation which is introduced to define a typical mooring system optimization problem. The mathematical formulation is used in a case study on a spread moored crane barge, operating in the vicinity of a jacket type platform, in order to minimize its surge motions towards the platform. For this purpose, a set of criteria regarding clearances between anchors and seabed preinstalled facilities (pipelines), and also between the crane barge and the jacket platform are presented and considered. An automatic process of repetitive analyses implementing a MATLAB code as an interface between the Genetic Algorithm and a mooring system analysis program is used, and an optimum solution is resulted by performing 4000 quasi-dynamic analyses in time domain. The effectiveness of the Genetic Algorithm in leading to an optimum mooring system pattern is studied and it is shown that using a proper formulation of the problem, the Genetic Algorithm can be a very useful tool for finding an optimum pattern for mooring systems in fields with constraints on anchor locations and vessel motions.

Agoes Priyanto

Papers

Manoeuvring prediction of pusher barge in deep and shallow water

A mathematical model on manoeuvrability of a LNG tanker in vicinity of bank in restricted water

Numerical Investigation on Aerodynamic Characteristics of a Compound Wing-in-Ground Effect

Experimental investigation of a wing-in-ground effect craft.

Mooring Pattern Optimization Using A Genetic Algorithm