Handbook of Turbomachinery Second Edition Revised - Ventech!

Required Performance Data
Test data required to produce turbomachine component performance maps
include rotational speeds, flow rates, pressure ratios, and measurements that
can be used for component efficiency calculations. In addition, the
aerodynamicist will want to know test parameters such as total pressure
and temperature radial distributions, static pressures on both the hub and
outer casing flow paths, dynamic measurements including running tip
clearances, dynamic pressures to quantify rotor blade shocks, when present,
and unsteady flow characteristics, and wake rakes to quantify pressure and
temperature profiles behind the stator assemblies.
Required Measurements
The selection of proper instrumentation is one of the most important aspects
of turbomachinery testing. The amount of instrumentation utilized on a test
rig is related directly to the information and data required. A more detailed
description of each of the measurement sensors is presented in a later
section.
Figure 4 shows a test rig cross-section schematic with typical
instrumentation that is utilized in classical aerodynamic performance
testing. Included are radial immersion total pressure and total temperature
rakes, numerous static pressure taps, selected radial surveys and wake rakes,
and dynamic response instrumentation. Not shown but of equal importance
are flow rate and speed measurements, in addition to ambient test condition
measurements. Stage performance is defined from total pressure, temperature,
flow rate, and shaft speed measurements. The total or stagnation state
of the fluid is defined as that state that would be achieved if the fluid were
Figure 4 Test rig instrumentation setup.
Copyright © 2003 Marcel Dekker, Inc.