They are opened and sustained in the open position by the force of velocity pressure, and closed by the force of gravity. 他是利用流体速度压力来开启和保持在开启的位置，并利用重力的作用来关闭。
You are now ready to develop wind pressure diagrams for a simple rectangular building. 现在你已经准备好计算一个简单的长方形建筑的风压图表。
The development of the code-based wind pressure diagrams, which are discussed in the next section, required many simplifying assumptions about these complex issues. 在下节讨论的，基于规范的风压图表的开发，需要许多对这些复杂的问题简化假设。
For the velocity survey the pitot-static tube is moved around the jet, and the dynamic pressure is measured at numerous stations. 为了测量速度，可把皮托静压管放在试验段内各个地方并测量多点上的动压。
Gusts can cause variations in the test section dynamic pressure, and in the distribution of dynamic pressure across the test section. 阵风会使试验段动压和试验段截面动压分布发生变化。
