2011年12月1日 · In Fig. 17, it is possible to visualize the P-52 QTF (T α (−) (ω, ω + μ)) values for heave (a) and pitch (d) computed by WAMIT ® by solving the full second-order problem. The diagonal line in the central part of the figure represents the QTF values for μ =0, which correspond to the mean drift forces.

2021年11月7日 · The heave QTF achieves its peak value when the frequency of the pair waves is around 0.32 rad/s. The peak value is around 5% of the maximum first-order heave force. Since the second-order wave forces are related to quadratic wave amplitudes, the contribution of second-order hydrodynamics will be significant in the waves with a large amplitude ...

Figure 9 presents an example of the heave QTF amplitude in the head sea under different working con- ditions. As expected, the sum frequency QTF has sharp peaks, while the difference frequency...

Heave QTF for 0owaveheading Fig. 10 shows the Heave QTF for 0o wave heading. The maximum values are found to be concentrated and lies on the diagonal. Consider the case of Heave QTF for 0owaveheading and take any point near to maximum value to get a difference frequency combination.

针对二阶波浪力的预报，Newman提出一种近似方法得到二次传递函数（Quadratic Transfer Function，QTF）。相较于直接计算完整的QTF矩阵，Newman近似方法利用定常二阶力近似低频二阶力，计算效率更高。

The wave drift load and sum frequency load are second order wave loads that act on objects subject to waves. They can be applied to a vessel and are calculated based on the dimensional wave drift QTF and sum frequency QTF data. For a detailed description of the theory see Faltinsen's book.

In the field of ship design and design of other floating structures, a response amplitude operator (RAO) is an engineering statistic, or set of such statistics, that are used to determine the likely behavior of a ship when operating at sea.

2021年7月15日 · In the present work, the difference-frequency wave loads on a restrained semi-submersible FWT subject to bichromatic waves are investigated by higher-fidelity tools (Computational Fluid Dynamics, CFD) and simplified engineering tools based on potential flow theory with Morison type drag.

2023年5月15日 · It was reported that the contribution from the second-order difference frequency wave force increases significantly as the water depth decreases. Thus, the full quadratic transfer function (QTF) method is recommended for shallow water while Newman's approximation may underestimate the motion responses.

Calculation of wave drift forces from full Difference-Frequency Quadratic Transfer Function (QTF) See also Second-order wave forces. By checking the Enable wave-current interaction checkbox, the zero-current QTF will be modified using Aranha’s formula at the time of running a simulation, based on the actual current velocity and direction.