scholarly journals EFFECT OF HULL AND ACCOMMODATION SHAPE ON AERODYNAMIC PERFORMANCES OF A SMALL SHIP

2019 ◽  
Vol 18 (4) ◽  
pp. 413-421
Author(s):  
Ninh Cong Toan ◽  
Ngo Van He

In marine transportation, aerodynamic performance is important for the ships, especially for the small passenger fast ships. It has affected the service speed, air resistance acting on hull, power energy as well as roll, pitch, yaw and stability of the ships. Moreover, the aerodynamic performance also directly affects the passengers, captains or employments who work on the ships. For a bad aerodynamic performance hull shape, it may make an accident in marine transportation. In this paper, the authors present a study on effect of hull shape on aerodynamic performance of a small passenger fast ship by using a commercial Computational Fluid Dynamics (CFD). Several hull forms with different shapes are proposed and computed to show their aerodynamic performances. From the comparison between different CFD results of the ships, the effects of hull shape on aerodynamic performances of the ships  are understood.

Author(s):  
Baojie Liu ◽  
Jiaxin Liu ◽  
Xianjun Yu ◽  
Dejun Meng ◽  
Wenbin Shi

Abstract The results of previous studies have proved that manufacture variations can cause a noticeable influence on compressor aerodynamic performance. The main objective of this paper is to investigate the influence rules and mechanisms of manufacture variations on supersonic/transonic blades aerodynamic performance. The variations used in this study were measured from some newly manufactured high-pressure compressors. In the present study, several blade sections with different design Mach number conditions are selected for further statistical analysis of measured deviation data. Therefore, some systematic errors in the deviation data have been revealed. Based on these data, the computational fluid dynamics (CFD) method has been used to obtain the aerodynamic performances of a large number of the measured blade elements. And then, the analysis of the influence rules of manufacture variations on blade aerodynamic performance in different Mach number conditions has been carried out. The present results indicate that the effects of manufacture variations on blade aerodynamic performance in the lower Mach number (0.8) condition are much more significant comparing to that in the higher Mach number (0.9∼1.2) conditions. Based on this, influence mechanisms of manufacture variations on positive incidence range and negative incidence range have been analyzed. The differences of influence mechanisms in different Mach number conditions are the focus of research.


2021 ◽  
Vol 21 (1) ◽  
pp. 37-46
Author(s):  
He Ngo Van ◽  
Thuan Truong Van

In this paper, we present a research on applying a commercial Computational Fluid Dynamics (CFD) code to determine interaction effect between hull and accommodation on wind drag of a container ship. For the high superstructure and large windward area ships such as container, wind drag acting on hull accounts for a large amount of total resistance. To clearly find aerodynamic performance and interaction effects on wind drag of a container ship, a full scale 1,200 TEU container has been used as a reference model. From results of comparison in the two computed cases of hull with and without accommodation, the interaction effects between hull and accommodation on aerodynamic performance and wind drag have been investigated. The targets of the paper has proposed a new solution to improve aerodynamic performances and reduce wind drag acting on the ship by reducing interaction effects between hull and accommodation.


2018 ◽  
Vol 7 (4.13) ◽  
pp. 202-204
Author(s):  
Mahadhir A Rahman ◽  
Mohammad Yazdi Harmin ◽  
Mohd Fuad Koslan ◽  
Mohd Rashdan Saad ◽  
Mohd Faisal Abdul Hamid

This paper presents the investigation of aerodynamic performance of inboard Store-X and Store-Y configurations on the X-plane aircraft model through computational fluid dynamics (CFD) analysis. The X-plane and Store-Y represent the default store and pylon integration while Store-X provides a possibility for other types of store to be integrated. These stores are loosely based upon the two most commonly used by the western and eastern blocks. The resultant lift, drag and moment forces are of interest in order to observe their impact with respect to the two different stores configurations. The finding shows that the aerodynamic impact with respect to Store-X installation on the inboard pylon station is insignificant when compared to default system, hence offers the safety of delivering the Store-X from the X-plane aircraft.


Author(s):  
H. Amini ◽  
M. Rad ◽  
A. Fakhraee

The powering requirement of a ship is one of the most important aspects of naval architecture. Traditionally, ships have been tested for hull resistance using hydrodynamic tank testing. But it is very time consuming, expensive, and has inherent scaling errors. Because of these reasons, today many vessels are sold on the market without any model testing. Another set of design tools are Computational Fluid Dynamics and parametric prediction. Computational Fluid Dynamics (CFD) codes are not yet wholly proven in its accuracy. Parametric predictions contain acquired data for a specific family of hull forms and use key hull parameters to evaluate a particular design. This tool is absolutely validating. In this work, parametric predictions tool has been used for velocity prediction of sailing boats and experimental equation has been used for hydrodynamic and aerodynamic calculation. However in this work from experimental equation from Delft towing tank has been used for hydrodynamic calculation but it is acceptable for more boats and ships. In this work velocity is predicted for a sailing boat with one rigid airfoil and sailing boat with cloth sailing. Rigid airfoil can control the velocity of boat. The maximum velocity occurred in 70 to 120 degree angle of courses. In Final stage, the velocity of boat is compared between sailing boat with rigid airfoil and cloth sail.


Author(s):  
T. Batuhan Korkut ◽  
Aytac Goren

This study focuses on the aerodynamic performances of two vehicles by Dokuz Eylul University Solaris Solar Car Project Team. The first vehicle (S7) is a solar-powered vehicle that is designed for World Solar Challenge and the second (D9) is an electric vehicle which is designed for Tubitak EV Challenge. Both vehicles are manufactured using polymer composites and challenged in mentioned races. In this research, a formal optimisation technique based on computational fluid dynamics (CFD) is used to determine the efficient aerodynamic structures under various scenarios. Results clearly show that strategists of the racing teams should take intoaccount the aerodynamic structure of the racing car. Especially before the races which based on efficiency, the apex line is determined, and mirrors should be replaced by back view camera.


2021 ◽  
Vol 11 (5) ◽  
pp. 7665-7672
Author(s):  
D. Bhatia ◽  
Y. Zhao ◽  
D. Yadav ◽  
J. Wang

This paper explores the use of sharkskin in improving the aerodynamic performance of aerofoils. A biomimetic analysis of the sharkskin denticles was conducted and the denticles were incorporated on the surface of a 2-Dimensional (2D) NACA0012 aerofoil. The aerodynamic performance including the drag reduction rate, lift enhancement rate, and Lift to Drag (L/D) enhancement rate for sharkskin denticles were calculated at different locations along the chord line of the aerofoil and at different Angles of Attack (AOAs) through Computational Fluid Dynamics (CFD). Two different denticle orientations were tested. Conditional results indicate that the denticle reduces drag by 4.3% and attains an L/D enhancement ratio of 3.6%.


2020 ◽  
Vol 8 (11) ◽  
pp. 930
Author(s):  
Ngo Van He ◽  
Ngo Van Hien ◽  
Van-Thuan Truong ◽  
Ngoc-Tam Bui

In this paper, we present our research on applying the commercial Computational Fluid Dynamics (CFD) code to investigate interaction effect between hull and accommodation on wind drag acting above the water hull surface of a full scale 1200 TEU container ship. With this purpose, aerodynamic performances and wind drag acting on the ship hull with and without accommodations have been computed. Analyzing the obtained CFD results, the interaction effect between hull and accommodation on aerodynamic performances and wind drag acting on the ship have been found. Various new accommodation shapes have been proposed for the original ship to reduce the interaction effect on wind drag. A drastic reduction in the interaction effect between hull and accommodation on wind drag acting on the ship has been achieved and the obtained results have been shown in this paper.


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