Dynamic response of a high-pressure reverse osmosis membrane simulation to time dependent disturbances

Dynamic responses of a high-pressure (80 bar) reverse osmosis (RO) membrane system to pulse disturbances in pressure, concentration and velocity are investigated. Responses are calculated using computational fluid dynamics (CFD) and are used to develop transfer function models using system identification methods. The response of the flux to pressure changes is described by a 3-pole/3-zero model for both positive and negative pressure pulses. The transfer function, which relates the flux response to concentration changes, is a 3-pole model, while the response to flow velocity changes is a single pole model.