Design Methods and Practices for Centrifugal Compressor Diffusers: A Review

The design of diffusers is a critical aspect of compressor performance, directly influencing pressure recovery, flow stability, and overall stage efficiency and operating range. This review paper provides an analysis of diffuser design principles, methodologies, and practical considerations in turbomachinery applications. The importance of diffusers in compressors is discussed, and the main types of diffusers are presented, highlighting, for each type of diffuser, their aerodynamic characteristics and operational advantages. Traditional empirical correlations and analytical models for diffuser geometry generation are reviewed, emphasizing their role in guiding preliminary design decisions. The integration of one-dimensional (1D) performance analysis methods with computational fluid dynamics (CFD) simulations is also discussed, illustrating how these approaches improve performance prediction and optimization accuracy. Design constraints are analyzed alongside performance trade-offs, highlighting the need to balance efficiency and stability. Overall, this review synthesizes existing knowledge on diffuser design in compressors, providing a structured framework for engineers and researchers to understand the key factors affecting performance and guiding the development of efficient, reliable diffuser configurations for real-world turbomachinery applications.