"A STUDY OF INTERACTION EFFECT BETWEEN TWO DIMENSIONAL WAVE DEVOURING PROPULSOR AND HULL"

吞浪推进器(WDP)是一种将海浪能量转化为能量的装置。WDP的想法是由该项目的首席研究员提出的，并于1986年进行了实验验证。1989年和1990年两次实船试验，均取得了成功。WDP主结构是位于船头下方的水翼，既能产生推力，又能限制船体的运动，起到阻尼器的作用。因此，WDP系统减小了海浪阻力增加，提高了海浪推进效率和海况。在可行性研究中，该装置可节约能源约50%，但目前对该系统的研究尚未展开。特别是WDP与船体的相互作用效果不明显。研究人员试图研究水翼与船体的相互作用效应，为了简化这一现象，引入了二维模型。将船体外形处理为位于圆形计算区域中心的矩形。自由表面的高度，即船体的右侧和左侧，随每个计算时间步长而变化。利用位势理论和边界元方法，建立了该问题的数学模型。为了模拟翼片产生的推力，在计算域中引入了等强度覆盖翼片表面并在每个时间步长的后缘脱落并以诱导速度运动的旋涡奇异性，为了解决这一问题，需要进行时间步长计算。因此，采用新引入的EWS发展了高速计算算法。从数值计算来看，相互作用取决于翼层深度。

The Wave Devouring Propulsor (WDP) is a device which converts wave energy to the trust. The idea of WDP was proposed by the head researcher of this project and tested experimentally in 1986. In 1989 and 1990, actual sea trial was conducted and succeeded using a small vessel with WDP.WDP main structure is a hydrofoil located under the ship bow which generates thrust and also restricts the hull motion as a damper. Therefore the WDP system decrease the resistance increase in waves and improve the propulsive efficiency in waves and sea kindness. This device will save the energy about up to 50% at the feasibility study.Nevertheless the research of this system is not developed now. Especially interaction effect between WDP and hull was not clear. The researcher tried to study the interaction effect between hydrofoil and the hull.For simplify the phenomena, two dimensional model was introduced. The hull configuration was treated as a rectangular shape which is located in a center of circular calculation domain. The height of free surface, right and left of the hull, changed by each calculation time steps. Using the potential theory and boundary element method, this problem was formulated. To simulate the thrust generated by the foil, vortex singularity was introduced in the calculation domain which covered the surface of the foil at the uniform strength and shedded at the trailing edge at he each time steps and moved with induced velocity.To solve the problem, time step calculation was necessary. Therefore high speed calculation algorithm was developed using newly introduced EWS.From the numerical calulation, the interaction depends on the foil depth.