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大家知道,在使用毛细管流量计时,当量程较大或毛细管长度与直径选择不当时,往往会在所测量范围内出现层流到湍流的过渡区域,在这个区域内气体流动处于不稳定状态,不能用来测定流量。在过去,每当遇此情况,人们常常用两根以上的流量计以求避开过渡区域解决问题。但是这样一来不仅不经济,而且在更换毛细管流量计的过程中常会带来额外的误差。为此我们根据流体力学原理,尽量设法减少毛细管端面效应的影响,采用金属圆锥在烧软的玻璃毛细管两端制成圆锥形的入口和出口以期推迟湍流区域的
As we all know, when using capillary flowmeter, when the range is larger or the capillary length and diameter are not properly selected, the transition zone of laminar flow to turbulent flow will often appear in the measuring range. In this area, the gas flow is in an unstable state. Used to measure the flow. In the past, whenever this was the case, two or more flowmeters were often used in order to avoid transitional areas and solve problems. However, this is not only uneconomical, but often introduces additional errors in the exchange of capillary flowmeters. To this end, according to the principle of fluid mechanics, we try our best to reduce the influence of the capillary end effect. Conical inlet and outlet are made on both ends of the soft glass capillary with metal cone to delay the