Numerical simulation study of liquid–liquid mixing of high-viscosity fluids under laminar flow in a reverse flow multi-stage Tesla valve.

This article focuses on the numerical investigation of liquid–liquid mixing performance and flow characteristics of high-viscosity fluids within multi-stage Tesla valves under laminar flow conditions. Using computational fluid dynamics and scalar transport modeling, the study analyzes the effects of Reynolds number (Re), Schmidt number (Sc), valve angle (α), and the number of Tesla valve stages (n) on mixing efficiency. Results show that increasing Re enhances mixing by intensifying Dean vortices, while higher Sc generally reduces mixing efficiency until a threshold (Sc ≥ 10^4) where flow dynamics dominate. Additionally, larger valve angles and more stages improve mixing by promoting fluid acceleration and vortex generation, with horizontal inlet configurations outperforming vertical ones. The study proposes a correlation formula for the mixing coefficient and recommends Tesla valves with more than three stages and angles greater than 45° for efficient mixing of high-viscosity fluids in constrained spaces.