Experimental Investigations on Hydrodynamic Characteristics of Tsunami-Like Hydraulic Bores Impacting a Square Structure

2022 ◽  
Vol 148 (3) ◽  
Marieh Rajaie ◽  
Amir H. Azimi ◽  
Ioan Nistor ◽  
Colin D. Rennie
Gang Wang ◽  
Rong Wan ◽  
Liuyi Huang ◽  
Fenfang Zhao ◽  
Xinxin Wang ◽  

Abstract In this present work, effects of three Euler angles (Angle of Attack (AOA), Angle of Trim (AOT), Angle of Pitch (AOP)) of vertical cambered otter board on hydrodynamic characteristics (drag coefficient (Cd), lift coefficient (Cl), center-of-pressure coefficients (Cp)) were studied based on numerical simulation combined with Kriging Response Surface Methodology (KRSM) and Multi-Objective Genetic Algorithm (MOGA). Wind tunnel experiments were carried out to validate the accuracy of response surface based on numerical simulation. It was demonstrated that AOA had prominent effects on Cd and Cl, while AOT and AOP had less effects. The working posture of otter board were recommended to lean inwards (0°∼6°) and forward (−10°∼0°) to improve the lift-drag ratio without sacrificing Cl. The influences of AOT and AOP on positions of center-of-pressure point were less significant than that of AOA and decreasing with the increase of AOA. In addition, response surface of hydrodynamic coefficients around the critical AOA was a decent indicator of occurrence of stall. Finally, three candidate cases were selected to satisfy the high working efficiency by MOGA, which was consistent with the above recommendations. This study provided a scientific reference of response surface experimental investigations methodology and the configuration of Euler angles of otter board.

S. M. Dmitriev ◽  
D. V. Doronkov ◽  
M. A. Legchanov ◽  
V. D. Sorokin ◽  
A. E. Khrobostov

Tgratinghis paper presents the results of experimental investigations of the influence of mixing spacer gratings with different types of deflectors on the coolant flow in the TVSKvadrat fuel assembly of the PWR-type reactor. Experimental model of the TVS-Kvadrat of the PWR reactor was made in complete geometric similarity with the full-scale cassettes. Studies were carried out by modeling the flow of coolant in the core with the use of an experimental stand; the latter was an aerodynamic open loop through which air is pumped. To measure the local hydrodynamic characteristics of the coolant flow, special pneumatic sensors were used that were able to measure the full velocity vector at the point by its three components. During the studies of the local fluid dynamics of the coolant, the transverse flow rates were measured; also, the coolant flow rates were measured by cells of the TVS-Kvadrat experimental model. The analysis of the spatial distribution of the projections of the absolute flow velocity made it possible to detail the pattern of the coolant flow behind the mixing spacing gratings with different variants of the deflector design, as well as to choose the deflector of the optimal design. Accumulated data base on the flow of the coolant in the TVS-Kvadrat fuel assembly formed the basis of the engineering justification of the structures of the active zones of PWR reactors. Guidelines for choosing optimal designs mixing spacing grids have been considered by designers of the “Afrikantov OKBM” JSC when they created implementations of the latest TVS-Kvadrat assemblies. The results of experimental studies are used to verify CFD-codes of both foreign and domestic origin, as well as the programs for detailed cell-by-cell calculation of active zones in order to reduce conservatism in the justification of thermal reliability.

2011 ◽  
Vol 354-355 ◽  
pp. 338-343
Qian Jun Li ◽  
Dong Ping Zhang

Experimental investigations on hydrodynamic characteristics of cylindrical pressurized spout-fluidizing bed were carried out. Two kinds of millet were used as bed materials. The operational pressure is 0.1MPa~0.4MPa (absolutely pressure). Five distinct flow patterns, i.e, fixed bed(FB), jet in fluidized bed with bubbles(JFB), jet in fluidized bed with slugging(JFS), spout with aeration(SA) and spout-fluidizing bed(SF) were identified. Effects of the static bed height and operational pressure on the flow pattern map were particularly studied. Typical flow pattern images obtained by a high- resolution digital CCD camera were presented for classifying these flow patterns. Typical flow pattern maps were plotted for describing the transitions between flow patterns with operating conditions

Xinliang Tian ◽  
Jianmin Yang ◽  
Xin Li ◽  
Tao Peng

Heave plates are installed in Spar platforms to improve the heave motion performance of the platforms. The heave plates not only increase the equivalent added mass of the platform but also provide extra damping to the system. This article presents an experimental study on the hydrodynamic characteristics of an isolate heave plate. The plate is forced to oscillate in the water at rest. The added mass and damping of the plate are used to represent its hydrodynamic characteristics. Influences of the thickness ratio, the plate shape, the corner radius and the porosity on the added mass and the damping coefficients of the heave plate are evaluated at various KC and β numbers.

2000 ◽  
Vol 21 (3) ◽  
pp. 322-328 ◽  

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-183-C5-186
M. VOOS ◽  
L. L. CHANG ◽  

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