IEC载荷工况与Bladed设置（12）DLC1.6
这篇文章介绍一下DLC1.6工况以及在bladed中怎么设置。
DLC1.6工况是极限工况，从工况表中可以看出1.6工况的轮毂处风速是NTM正常湍流风的平均风速是在切入和切出风速之间，波浪是SSS恶劣海况，风和波浪的方向是同向且是单向的，海流是正常流，水位是正常水位范围，安全系数是正常。
DLC1.6 embodies the requirements for ultimate loading resulting from normal turbulence (NTM) and severe sea state (SSS) conditions. Response calculations shall take proper account of the dynamic response to wind, wave and current loads as well as non-linear wave kinematics. To ensure this the load case shall be analysed using simulations of turbulent inflow in combination with stochastic sea states which each include at least one non-linear wave of height equal to the extreme wave height appropriate to the SSS. Sea state parameters are determined as described in 6.3.3.2.3. Clause 7.5.6 specifies how simulations shall be performed to fulfil the requirements of DLC1.6.DLC1.4和1.5规定了可DLC1.6包含了由正常湍流模型（NTM）和恶劣海况（SSS）引起的极限载荷。响应计算应适当考虑对风、波浪、海流载荷及非线性波动力学的动态相应。为确保该载荷，应结合湍流和随机海况模拟（至少一个非线性波高等于SSS的极大 波高）进行载荷分析。6.3.3.2.3中明确了海况参数。7.5.6规定了满足DLC1.6要求的仿真方法。
Simulation requirements
for DLCs 1.6, 6.1, 6.2, 6.3, 7.1, and 8.2, at least six 1-hour constrained wave simulations shall be performed as described in C.7.3. Alternatively six groups of six 10-min simulations each may be performed. Where each group of six is equivaient to one 1-hour simulation. For at least one 10-min simulation within each group of six the hub height mean wind speed shall be taken as the 10 min value with N-year return period while for others the 1-hour N-year return period mean wind speed value with an appropriate asspciated turbulence level may be used. In a similar manner, at least one 10-min aimulation within each group of six shall contain the N-year return wave height, HN. The significant wave height shall be taken as the value with an N-year return period for each simulation. Other approaches may be taken if the designer is able to demonstrate that the estimated extreme reponse is not less extreme than that obtained with 1-houre realization. It is noted that for assessment of cyclic degradation of soil properties, more simulation may be required, but for the design load calcution, six simulation are sufficient.
仿真要求
在DLC1.6、6.1、6.2、6.3、7.1和8.2中，应根据C7.3中描述开展至少6个1小时的约束波仿真，或者进行6组6次10分钟的仿真。每组的6个仿真等效为1小时仿真。对于每小组内，至少一个10分钟的仿真需要考虑N年重现期的10分钟平均风速作为轮毂中心风速进行仿真，其余的可考虑N年重现期1小时的平均风速进行仿真，同时需要考虑适当的湍流水平。类似地，对于每小组内，至少一个10分钟的仿真包含N年重现期波高HN。N年重现期的有义波高应在每个仿真中考虑。其他方法可采纳，前提是设计者能证明估计的极限载荷不小于实际中1小时的极端载荷。值得注意的是，对于土壤特性的循环退化评估，可能需要更多的仿真，但对于设计载荷计算，六个仿真是足够的。
接下来就讲讲DLC1.6工况怎么在bladed中计算。
首先是风的设置，额定风速以10.8米每秒举例, 风速是取额定风速和额定风速正负2米每秒。偏航误差取-8、0、和8三个方向。每个风速取六个波浪取恶劣海况（SSS），方向和风的方向相同， 有义波高和谱峰周期取50年一遇的值。流取与风速相对应风生近表层流的值。风和波浪的设置以前都讲了，注意潮位在平均水位的正负2之间。
下图举了1.6工况额定风速为10.8米每秒的例子。
仿真时间用600秒，初始时间30秒。
