Hydrodynamic study of heeled double-stepped planing hulls using CFD and 2D+T method

Dynamic of a planing hull in regular waves: Comparison of experimental, numerical and mathematical methods

In the current hydrodynamic research relating to planing hulls, the stern flap and steps are generally considered to be two independent resistance reduction measures. Limited research has focused on the coupled effects of flaps and steps. Therefore, experimental and numerical simulation methods are carried out in this paper to explore the influence of the flap mounting angle coupled with the steps. A series of model towing tests were implemented for a double-stepped planing hull with 2°, 3° and 4.5° flap angles. The test results show that, as the mounting angle increased, the low speed resistance performance was improved and the porpoising critical speed was delayed, with a slight resistance cost. Based on the tests, a numerical simulation method was established with volume Froude numbers ranging from 0.88 to 5.20. The simulated hull flow field showed good agreement with the testing data. The simulation results suggest a cavity induces the negative pressure after the steps; the cavity core region is the air phase, and this expands with the air–water mixture flow. The cavity also causes wetted surface reduction and pressure distribution changes. Finally, comparisons of cavities after-steps and load coefficients of different planing surfaces among models were considered. Numerical results analysis gave distinct interpretations for the experimental phenomenon of porpoising critical speed increasing with a slight resistance increment.

Experimental and Numerical Research on the Influence of Stern Flap Mounting Angle on Double-Stepped Planing Hull Hydrodynamic Performance

In this article, a mathematical model based on the 2D+T theory has been developed to predict the performance of two-stepped planing hulls in calm water. It has been attempted to develop a mathemati...

Development of a 2D+T theory for performance prediction of double-stepped planing hulls in calm water:

Numerical study on a heeled one-stepped boat moving forward in planing regime

Performance Prediction of Two-Stepped Planing Hulls Using Morphing Mesh Approach

Comparison between the Dynamic Behavior of the Non-stepped and Double-stepped Planing Hulls in Rough Water: A Numerical Study

ARTICLE INFORMATION ABSTRACT Original Research Paper Received 09 October 2016 Accepted 15 December 2016 Available Online 04 January 2017 Development of wave energy convertors (WEC) is one of the main challenges that naval architectures have recently encountered. One of the most important approaches before construction of WECs is the evaluation of their conceptual models in computational fluid dynamics (CFD) software. Therefore, in the current article, an innovative model of wave energy convertor is presented and hydrodynamic performance of proposed model in the Persian Gulf has been examined. For accurate simulation of dynamics of WEC, mesh morphing technique is utilized. Since the presented WEC is an innovative design and there is no experimental result for validation purpose, we have tried to verify the numerical setup using similar experimental problems which have the various characteristics of the considered problem. Then, several different geometries including flat and foil pedals, and big and small semispherical pedals as a part of WEC have been analyzed, numerically. Small semi-spherical pedal has been determined as the best possible geometry. Number of pedals is another parameter which has been studied and eight pedals model has been recognized as the optimum choice. Finally, optimum WEC has been simulated in nine different waves and the results have been presented.

Arman Esfandiari

Papers

Performance Prediction of Two-Stepped Planing Hulls Using Morphing Mesh Approach

Comparison between the Dynamic Behavior of the Non-stepped and Double-stepped Planing Hulls in Rough Water: A Numerical Study

Numerical simulation of a near-shore rotating wave energy converter