转换准则 meaning in English

switching criterion

According to different flow patterns , a new transferring rule for oil - water two phases system flowing model in pipes is built in including the stability rule for stratified flow patterns and transferring border and anti - phase border for deconcentrating patterns and mixture patterns
根据管内油、水两相流流型特征，建立了新的油、水两相管流流型的转换准则。它包括：分层流型的稳定性准则、分散流型和混合流型的转换边界及反相界线。