Transient simulation or two-phase flows in pipes

Transient simulation of two-phase gas-liquid flow in pipes requires conside rable computational efforts. Until recently, most available commercial code s are based on two-fluid models which include one momentum conservation equ ation for each phase. However, in normal pipe flow, especially in oil and g as transport, the transient response of the system proves to be relatively slow. Thus, it is reasonable to think that simpler forms of the transport e quations might suffice to represent transient phenomena. Furthermore, these types of models may be solved using less time-consuming numerical algorith ms.