吃水系數 的英文怎麼說
中文拼音 [jíshuǐxìshǔ]
吃水系數
英文
draft coefficient-
The calculated drafts covers the whole possible ship draft in the large amplitude motion ; secondly, the research creates and solves the ship large amplitude motion equations. on the one hand, the actual calculation takes into account the coupling between the different motion modes, on the other hand, in the process of calculation of the ship hydrodynamic coefficient, it considers the influence of the nonlinear factor. the hydrodynamic coefficient used in the calculation of froude - krylov force, diffraction force and radiation force changes instantaneously following the draft, and the hydrostatic buoyancy is computed very accurately for the instantaneous immerse hull
本文的研究分為二個部分:首先利用frank源匯法計算水動力系數,計算包括不同吃水時的附加質量和阻尼系數,吃水范圍涵蓋了船舶大幅度運動時所有可能的吃水;然後建立和求解船舶大幅度運動方程,在實際計算時一方面考慮了運動模態之間的耦合,另一方面在計算水動力時,考慮了非線性因素的影響。 froude - krylov力、輻射力、繞射力中的水動力系數隨吃水瞬時變化,靜浮力的計算精確到船體瞬時濕表面積,最後用四階龍格?庫塔方法在時域內求解船舶運動方程,並進行了載荷計算。Based on the analysis and calculation of ship resistance, according to the main factors influencing the resistance, such as sailing speed, water depth and ship draft ratio, and coefficient of sectional form, the deepwater, shallow water and restricted channel are defined by the coefficient factor
摘要通過對船舶阻力的分析和計算,根據影響阻力的主要因素,航速、水深與船吃水比、斷面系數,由換算系數來界定深水、淺水與限制性航道。In general, the upward amplitude curve " curvature is larger, and it changes quicker. on the contrary, the downward is smaller and slower ; because the flare force contains the square of the wave elevation velocity, it results in an difference between the flare force frequence and the associated moving frequence ; the flare force decreases the downward amplitude of heaving oscillations ; the speed of ship has an ignorant effect on the peak values of three calculated values, but there is an obvious effect on the oscillating frequence ; the wave amplitude has an effect on the ship motion, and there is an linear relation between the oscillating amplitude and the wave amplitude on the whole. by the way, there are some experiences and lessons according to the progress calculation : before the calculation of the ship motion, we should checkout the balance in a calm water firstly, namely, the whole displace of ship and the longitudinal position of the center of gravity must be consistent with the draft in calm water, or else, the calculation may show the " floating " phenomenon ; the mixed language programming has a lot of virtues, but it exists a fatal limitation - the debug of dll
研究表明:在某些頻率范圍內相關水動力系數基本不隨吃水變化,只有超過某一頻率后水動力系數的值才會出現差異;在橫搖方向,水動力系數並沒有隨著吃水的變化發生規則變化,而是出現了波動現象;近船首剖面的水動力系數計算表明,水動力系數的波動非常大,並遠遠偏離了平均位置的水動力系數值,值的變化速率也不盡相同,總的看來,上振幅曲線曲率較大,變化較快,下振幅曲線曲率較小,變化較慢;外飄力和波面運動的速度的平方項有關,導致其振動頻率和相應運動方向的頻率不同;外飄力使升沉向下運動的幅值減小;船速對三個計算量的峰值影響甚微,但對振動頻率有明顯影響;波幅對船舶運動的影響是明顯的,船舶運動的幅值基本上和波幅成線性關系。
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