Introduction

Fluid machinery is classified as those devices that transform fluid energy to shaft work or vice versa. It is also divided into two categories: turbomachinery and positive displacement fluid machinery. This chapter is mostly concerned with turbomachinery that can also be categorized according to the change in the flow direction through the impeller. It introduces aerodynamic/ hydrodynamic analysis and design methods for the evaluation of the basic performance of turbomachinery. Design requirements and operating conditions of a turbomachine need to be specified in terms of flow capacity, revolutions per minute (RPM), pressure rise, efficiency, noise level, and inlet flow conditions. Meanline performance analysis is performed using thermodynamic equations, flow deviation, and pressure loss models to estimate roughly the effects of design variables on aerodynamic performance. Systematic optimization using high‐fidelity analysis produces high‐performance and reduces computational and experimental expenses in turbomachinery design.