【摘要】 在遵循雷诺准则的长大隧道模型试验中，保证模型与原形的压力降相等是当前的难题。为此，本文提出在出风口处安装节流口而模拟模型隧道长度延伸。在隧道通风模型上，完成了5组节流口面积比的试验，得到了平均风速、静压和节流口处风速；以此为边界条件，节流口面积比进一步扩展至9组，量化面积比对流场参数的影响，建立了面积比与节流口局部阻力的关系。结果表明：面积比在0.108～0.192时，隧道模型当量长度计算值骤增；小于0.108时，当量长度计算值随通风机频率变化而呈现发散，确定出了计算模型的面积比适用范围；最后，得到了适用于面积比不小于0.108的隧道当量长度计算式。该公式极大放宽了隧道通风模型长度，提供了重要的实验流体力学参考。更多还原

【Abstract】 Ensuring that the pressure drop between the model and the original shape is equal is currently a challenge in long tunnel model tests that follow the Reynolds criterion. Therefore, this article proposes to install a throttling port at the air outlet to simulate the extension of the model tunnel length. On a tunnel ventilation model, complete 5 sets of experiments on the area ratio of the throttle opening to obtain the average wind speed, static pressure, and wind speed at the throttle opening; Using this as the boundary condition, the area ratio of the throttling port was further expanded to 9 groups, quantifying the influence of the area ratio on the flow field parameters, and establishing the relationship between the area ratio and the local resistance of the throttling port. The results show that when the area ratio is between 0.108 and 0.192, the calculated equivalent length of the tunnel model increases sharply; When it is less than 0.108, the calculated value of equivalent length diverges with the variation of fan frequency, determining the applicable range of area ratio of the calculation model; Finally, a formula for calculating the equivalent length of tunnels with an area ratio of no less than 0.108 was obtained. This formula greatly broadens the length of the tunnel ventilation model and provides important experimental fluid dynamics references.更多还原