Introduction

Turbomachinery Flow Modeling

Rotating Machinery

Incompressible Applications Hydraulic turbines: spiral casing, distributor, runner, draft tube

Pumps: impeller, volute, seals, crossovers

Mixing tanks

Inducers

Electric motors

Compressible Applications Compressors: inlets, impellers (single and multi-stage), volutes, disk cavity,

crossovers, return channels

Turbines: inlet scroll, nozzle, blade rows, disk cavity

Use of Rotating Machinery

Power Extraction Extract energy from a moving stream and convert to useful work

Examples: hydraulic turbines, gas turbines, steam turbines, expanders

Change State Change pressure/temperature/velocity of some fluid, as required by a

system or process

Examples: pumps, compressors

Use of Rotating Machinery

Moving Fluid Convey fluid from one location to another, as part of a system or process

Examples: fans, blowers, propellers, pumps

Mixing Mix different fluid streams together

Examples: various types of rotary mixers

Power Transmission Torque converters and fluid couplings

Classification of Turbomachinery

Axial machines Flow through the machine is (in general) aligned with the axis of rotation

Examples: propellers, axial fans/compressors/turbines, swirlers

Centrifugal machines Flow through the machine is (in general) perpendicular to the axis of

rotation

Examples: liquid pumps, centrifugal fans/compressors, radial turbines

Mixed flow machines Flow through the machine is somewhere between axial and centrifugal

Example: mixed flow compressor or pump

Turbomachinery Classification Examples

Axial Compressor Centrifugal Pump Mixed Flow Pump

Stage 1 Stage 2 Stage 3 Stage 4Inlet Outlet

Turbomachinery Classification Examples

Four stage turbine

stator

rotor

BY NUMBER OF STAGES

Turbomachinery Classification Examples

interface

Single Component(blower wheel blade passage)

Multiple Component(blower wheel + casing)

BY NUMBER OF COMPONENTS

Characteristics of Rotating Machinery Flow

Stationary and rotating components

Usually complex flow with significant amount of secondary flows

Flow is usually turbulent (but sometimes laminar, sometimes both, or sometimes unknown!)

Wide range of temperatures, pressures, and velocities

Newtonian and non-Newtonian liquids

Incompressible to supersonic flows

Characteristics of Rotating Machinery Flow

Swirling flows

Simple state relations (ideal fluid, constant property liquid) to complex thermodynamics and properties (R134a, steam)

Unsteady (periodic unsteadiness, usually not random)

Single and multi-phase flows

Heat transfer (and sometimes mass transfer and chemical reaction involved)