Thermo‐Fluid‐Structural Coupling Analysis of Twin‐Screw Compressor Rotors Under Variable Operating Conditions

ABSTRACT Twin‐screw compressors are prone to rotor failure under complex multi‐physics loads. This study establishes a thermo‐fluid‐structural coupling framework to analyze rotor behavior under varying operating conditions. A one‐way sequential coupling approach integrates CFD and FEA to simulate pressure, temperature, deformation, and stress fields. Parametric studies cover discharge pressures (0.2–0.7 MPa) and rotational speeds (2000–7000 rpm). Results show that deformation increases monotonically with pressure, while von Mises stress exhibits a non‐monotonic trend with a minimum at 0.3 MPa, indicating an optimal force‐balance state. Rotational speed significantly affects internal pressure but induces a non‐monotonic temperature distribution due to competing compression and residence‐time effects. The identified operating point (0.3 MPa at 3000 rpm) represents the structural optimum that minimizes mechanical stress on the rotor, thereby providing direct guidance for rotor design and fatigue life assessment. It should be noted that this condition is derived from structural optimization only; comprehensive compressor performance optimization would require simultaneous consideration of thermodynamic efficiency, leakage losses, and vibration characteristics. This work offers a validated numerical framework and practical insights for enhancing twin‐screw compressor reliability. The framework's predictive capability for thermo‐mechanical responses is substantiated through comparison with experimental measurements from analogous operating conditions, confirming its suitability for engineering design optimization.