In a pitot - tube , a small filament of the fluid is brought to rest in a small - bore tube , the impact pressure being measured against the static pressure of the fluid in an outer tube 在全压管内，注入的液体流丝停留在一个小内径管内，全压通过外管内液体的静压测得。
By the multiple objective optimization , the diffusion angle of the ventilator volutes with high efficiency , low noise and high total pressure of the ventilators was calculated and selected according to the experimental data 摘要根据实验数据，采用多目标最优化的方法，对效率高、噪声小、全压大等性能指标皆好的通风机蜗壳扩压角进行了理论计算选择。
Blower performance testing is the course of changing working states , measuring testing datas , calculating performance parameters and plotting performance curves which processed under the certain rotate speed . it is important to inspecting finished production and designing new production 风机性能试验是在风机转速不变的情况下，改变风机运行工况、测量试验数据、计算风机性能参数并绘制性能曲线(流量?全压曲线、流量?功率曲线、流量?效率曲线)的过程。
