T型靠背风速管研制及其在动车组流量测试中的应用

为解决动车组底板和部分通风通道流速方向变化、安装空间狭小而无法采用传统测速仪器的问题,研制了一种新型具有较佳全压孔形式的微型T型靠背风速管,通过风洞试验标定的方法分析了不同弯管段长度、不同风偏角以及不同空气流速对流速管流速系数的影响,并在动车组新风通道流量测量的实车试验中对其工作特性进行了验证。确定了弯管段最佳长径比为L/D=2,该结构尺寸下,随着动压的改变,流速系数波动不明显,最大变化率为1.34%,平均流速系数为0.741;风偏角在10°范围以内变化时流速系数变化不大,最大相差6.12%;在动车组新风通道流量测试的实车试验中,测得的流量值与额定风量值之间的最大误差为4.03%。这种新型靠背管结构尺寸简单且具有双向性的特点,对流速及风偏角变化敏感程度较小,工作稳定可靠,测试精度较高。

Study of the T type back-supported tube and its application in EMU flow test

In order to solve the problem that the traditional velocity measurement instruments can not be applied to Electric Multiple Units （EMU）,because of the reverse of the flow and the limited space,a new type tube called T back-supported tube was developed.It has better total port.By the wind tube test,the correlation between velocity coefficient and the different variables such as bend segment length,wind yaw angle,flow velocity and so on was discovered.A verification flow test of the flesh air tube in the full-scale experiment can prove its excellent characters.The best ratio between length and diameter of the bend segment is 2,and under this size, the velocity coefficient under the dynamic pressure 138Pa was only changed 1.34% as the pressure varied.The average velocity coefficient in the range of 353Pa of the dynamic pressure was 0.741.The wind yaw angle variation does have effect to the velocity coefficient of the T type back-supported tube.It is indicated that 10 degrees increasing can make the velocity coefficient decrease 6 .1 2%.The T type back-supported tubes were well applied in the EMU fresh-air tube flow testing;the errors between the testing results and the rated values were all within 4.02%. It is pointed that while the structure of the T back-supported tube is simple and symmetric,it is also less sensitive to the velocity and wind yaw angle variation.The tube worked stable and reliable and the result was also precise.