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该文在室内无风状态下,开展了两种小模型消防水炮在不同仰角,不同工作压力下的射流轨迹测量试验。基于单水滴空气中飞行的轨迹计算,采用指数增长形式的空气阻力模型,提出仅含1个待定系数b的射流轨迹预测方法,计算了各个工况下几种系数b取值的射流轨迹。以各个测量点的射流轨迹高度与计算轨迹的高度之差,其算术平均值越小,标准偏差?越小为约束条件,获得预测模型中待定系数b的合适取值,并将该合适b值下计算的射程、射高与实验值对比。结果表明直流式消防水炮b值取0.01,导流式水炮b值取0.08能获得很好的预测精度,试验值与计算值对比,直流式水炮的测点高差算术平均值小于0.25 m,射程预测误差小于1.3%,水射流的射高预测误差小于1.2%,导流式水炮测点高差算术平均值小于0.3 m,射程误差小于2.98%,射高误差小于4.7%。该文的方法可用于开展远射程消防水炮的射程预估。
Under the condition of no wind in the room, this paper carried out the test of jet trajectory of two small model fire guns at different elevation angles and different working pressures. Based on the trajectory calculation of single droplet air flight and the exponential growth model of air resistance, a jet trajectory prediction method with only one undetermined coefficient b is proposed. The trajectories of several coefficients b under each condition are calculated. Taking the difference between the height of the jet trajectory and the height of the calculated trajectory at each measuring point, the smaller the arithmetic mean value and the smaller the standard deviation? Are the constraints, the suitable value of the coefficient to be determined b in the predictive model is obtained, and the appropriate b value Under the calculated range, shooting height and the experimental value of contrast. The result shows that the b value of DC fire water monitor is 0.01 and the b value of diversion water monitor is 0.08 to obtain good prediction accuracy. Compared with the calculated value, the arithmetic mean of the altitude difference of DC water monitor is less than 0.25 m, the prediction error of range is less than 1.3%, the prediction error of shot height of water jet is less than 1.2%. The arithmetic average of the height of the guide water cannons is less than 0.3 m, the range error is less than 2.98% and the shot error is less than 4.7%. This paper’s method can be used to carry out long-range fire monitor range projection.