Design and optimization of an axial turbo-vapor compressor through three- dimensional flow analysis and loss modeling

The novelty of the TVC lies in its integrated axial design, in which a compressor creates a vacuum in the evaporator, thereby lowering the evaporation temperature of water from 100°C to ~85°C. The system is started by an external motor, and once operational, the expansion of vapor in the turbine directly drives the compressor into a self-sustaining loop, thereby eliminating the need for inlet/outlet guide vans and reducing aerodynamic losses and cost. Enhancing TVC efficiency is significant because of its direct impact on system reliability, energy conversion efficiency, and overall operational costs. A comprehensive three-dimensional design and optimization methodology was employed, combining mean-line analysis, blade geometry generation, and detailed CFD simulations using ANSYS CFX. The investigation accounts for real-world loss mechanisms, including incidence and deviation losses, secondary-flow losses, and tip-clearance losses, enabling a realistic performance assessment. The results show that the optimized blade profiles achieve compressor and turbine total-to-total isentropic efficiencies of up to 97.6% and 86.9%, respectively, with a pressure ratio reaching 1.49 and a specific work of approximately 152.5 kJ/kg. Parametric analysis of turbine stagger angle reveals its strong influence on flow uniformity and efficiency, with improper stagger causing measurable degradation due to increased secondary losses. These findings indicate that careful three-dimensional blade optimization substantially enhances TVC performance. The novelty of this work lies in integrating detailed loss modeling with full 3D CFD-based optimization, moving beyond traditional one-dimensional or simplified approaches commonly reported in the literature. The proposed methodology provides a robust design framework for advanced energy and desalination applications.