scholarly journals ENERGY EXTRACTION UTILIZING THE PITCHING MOTION OF A FLOATING VESSEL.

2008 ◽  
Vol 24 ◽  
pp. 117-122
Author(s):  
Pallav KOIRALA ◽  
Kesayoshi HADANO ◽  
Keisuke TANEURA
2019 ◽  
Vol 9 (3) ◽  
pp. 384
Author(s):  
Yulu Wang ◽  
Fahui Zhu ◽  
Yonghui Xie

The effect of non-sinusoidal motion which influences the energy extraction performance of foil is considered in this paper. Two oscillation motions, the combined non-sinusoidal plunging and sinusoidal pitching motion, as well as the combined non-sinusoidal pitching and sinusoidal plunging motion, are selected to investigate the oscillation process of two-dimensional parallel foils numerically. The optimal oscillation motion and average power coefficient at different combined motions are gained. The effects of the plunging motion and pitching motion at different oscillation motions are analyzed, and the evolution law of the foil lift force and vortex field are obtained. It is indicated that the non-sinusoidal motion has a significant influence on energy extraction. When the motion is combined (non-sinusoidal plunging and sinusoidal pitching motion), the best extraction performance is gained at Kh = −0.5. The maximal CPm is 0.375 and the maximal η is 0.188. When the motion is combined (non-sinusoidal pitching and sinusoidal plunging motion), the maximal CPm is 0.623 and the maximal η is 0.312 which appear at Kθ = 2. For the same frequency, the more the plunging motion is similar to the sinusoidal motion, the more energy is extracted by foils. While the more the pitching motion approximates to the square wave, the worse the achieved extraction performance is.


Author(s):  
Wei Jiang ◽  
Yulu Wang ◽  
Yonghui Xie ◽  
Di Zhang

A new concept of power generator using two oscillating foils in parallel configuration to extract energy from fluid is proposed and numerically tested in the present study. The theoretical performance of the turbine in this form is investigated through unsteady two-dimensional laminar-flow Navier-Stokes simulations. The effect of the interaction between the two foils is studied at different pitching amplitudes and phase differences between the two foils. The energy extraction performance, instantaneous force coefficients and flow details are compared between single foil and dual foils, and thus the mechanism of performance improvement by wing-in-ground effect is revealed. Two different kinds of asymmetric sinusoidal motions are utilized to further improve the performance of the turbine. Numerical results indicate that anti-phase mode can achieve higher power coefficient than the in-phase mode. The contracted passage under anti-phase mode helps produce larger lift force and power coefficient. The maximum power coefficient per foil for anti-phase dual foils is 1.4% higher than that of single foil. The asymmetric sinusoidal pitching motion in phase can improve the synchronization between plunging velocity and lift force and thus further enhance the energy extraction performance by 1.3%. Besides, the pitching motion with asymmetric amplitude also can increase the power coefficient somehow, but the improvement is very limited.


Author(s):  
Manoj Prabakar Sargunaraj ◽  
Dibya Raj R. Adhikari ◽  
Carlos E. Soto ◽  
Samik Bhattacharya

2021 ◽  
pp. 0308518X2110266
Author(s):  
Neil Argent ◽  
Sean Markey ◽  
Greg Halseth ◽  
Laura Ryser ◽  
Fiona Haslam-McKenzie

This paper is concerned with the socio-spatial and ethical politics of redistribution, specifically the allocation of natural resources rents from political and economic cores to the economic and geographical peripheries whence the resource originated. Based on a case study of the coal seam gas sector in Queensland's Surat Basin, this paper focuses on the operation of the Queensland State Government's regional development fund for mining and energy extraction-affected regions. Employing an environmental justice framework, we critically explore the operation of these funds in ostensibly helping constituent communities in becoming resilient to the worst effects of the ‘staples trap’. Drawing on secondary demographic and housing data for the region, as well as primary information collected from key respondents from mid-2018 to early 2019, we show that funds were distributed across all of the local government areas, and allocated to projects and places primarily on a perceived economic needs basis. However, concerns were raised with the probity of the funds’ administration. In terms of recognition justice, the participation of smaller and more remote towns and local Indigenous communities was hampered by their structural marginalisation. Procedurally, the funds were criticised for the lack of local consultation taken in the development and approval of projects. While spatially concentrated expenditure may be the most cost-effective use of public monies, we argue that grant application processes should be open, transparent and inclusive, and the outcomes cognisant of the developmental needs of smaller communities, together with the need to foster regional solidarity and coherence.


2021 ◽  
Vol 228 ◽  
pp. 108901
Author(s):  
Xiao-Dong Bai ◽  
Ji-Sheng Zhang ◽  
Jin-Hai Zheng ◽  
Yong Wang

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