THE USE OF ORIFICES TO CONTROL THE FLOW RATE OF GASES
THE USE OF ORIFICES TO CONTROL THE FLOW RATE OF GASES
复制标题
使用孔板控制气体流量
DOI：
--
复制
发表时间：
1979
期刊：
影响因子：
--
通讯作者：
W. Day
中科院分区：
文献类型：
--
作者：
K. Parkinson;W. Day
(1)常用于光合作用、呼吸作用和蒸腾作用研究的恒定体积的气体流速可以通过使用商业上可获得的小孔来获得。(2)当节流孔下游与节流孔上游的绝对压力比小于0-47（临界压力比）时，体积流量与下游压力无关。体积流率和绝对上游压力之间的关系中的轻微非线性是由于气体与理想气体行为的偏差，以及直到通过孔口的流量的雷诺数超过30 000才遵循流量压力之间的理论关系的事实。体积流量与绝对温度的平方根成比例。(3)体积流率和孔口直径（50-175 μ m）之间的预期关系在此针对排放到大气的孔口导出，上游绝对压力在0.24和0-9 MPa之间。
(1) The flow rates of gases, at constant volume, that are commonly used in studies of photosynthesis, respiration and transpiration, can be obtained by using small orifices that are commercially available. (2) When the ratio of the absolute pressure downstream of the orifice to that upstream of the orifice is less than 0-47 (the critical pressure ratio), the volume flow rate is independent of downstream pressure. A slight non-linearity in the relationship between volume flow rate and the absolute upstream pressure is due to deviation of the gas from ideal gas behaviour, and to the fact that the theoretical relationship between flow pressure is not followed until the Reynolds' number for flow through the orifice exceeds 30 000. The volume flow rate is proportional to the square root of the absolute temperature. (3) The expected relationship between volume flow rate and orifice diameter (50-175 pm) is here derived for orifices discharging to atmosphere, with upstream absolute pressures between 0.24 and 0-9 MPa.