环形狭缝通道内气液两相环状流流动特性

建立了环形狭缝通道内气液两相环状流的理论模型 ,该模型计及环状流气芯流动的可压缩性、气液两相间的相滑移、气相对液滴的夹带作用等因素 .考察了两相流质量流量和干度对压降、液滴速度相对变化和狭缝喉部气芯通流面积的影响 .用建立的理论模型对空气 -水两相环状流通过环形狭缝的两相压降进行预测 ,预测值和试验值吻合良好

FLOW CHARACTERISTIC OF GAS-LIQUID TWO-PHASE ANNULAR FLOW THROUGH ANNULAR NARROW PASSAGE

A mathematical model for predicting the pressure drop characteristic of gas-liquid two-phase annular-mist flow through an annular narrow passage is presented. The flow model takes into account the compressibility of the gas core fluid, the phase slip and droplets entrainment in the gas core flow. The assumed vena contracta effect of the mist core flow through annular narrow passage is considered by applying discharge coefficient for pure air flow. A force balance method is applied to spherical droplets to calculate the phase slip ratio of the mist core flow at the throat cross-section of the annular narrow passage. The effects of two-phase mass flow rate and mass flow quality on pressure drop, cross-section area of the core flow at throat, relative variety of droplet velocity are disscussed in detail. To verify the proposed model the computed two-phase pressure drop is compared with experimental data of air-water mixture for different annular narrow passages and different inlet conditions,and a good agreement between the simulation results and experimental ones is obtained.