The Role of Pressure Scanners in Aero-Engine Testing

In aero-engine whole-engine testing, pressure measurement is one of the key steps and is crucial for evaluating 

engine performance and reliability. The pressure testing system in aero-engine whole-engine testing is achieved 

by pressure probes guiding gas through pressure transmission tubes into a pressure scanner for measurement. 

As the core equipment of the pressure measurement system, the performance and accuracy of the pressure scanner 

directly affect the reliability of test data. Today, let's delve into the advantages and disadvantages of different 

pressure transmission methods and introduce you to an exceptional Gensors pressure scanner.

The pressure testing system consists of pressure probes, pressure transmission tubes, and a pressure scanner. 

Pressure probes guide gas through the tubes into the pressure scanner for measurement. Pressure probes are 

divided into two types: total pressure probes and static pressure probes. Total pressure probes feature a 

stagnation structure facing the airflow, bringing the flow velocity to zero and converting kinetic energy into internal 

energy. Static pressure probes need to be relatively stationary to the airflow and are typically measured through 

holes in the wall surface.

A pressure scanner is a multi-channel sensor used for multi-point pressure measurement and acquisition. The 

dynamic characteristics of the pressure transmission tubes significantly impact the performance of the testing 

system. Long pressure transmission tubes can limit the system's dynamic performance. Research shows that due 

to the inertia of the gas inside the tubes, the natural frequency of the pressure transmission tubes is much lower 

than that of the pressure sensor, making their dynamic characteristics more significant in influencing the 

performance of the pressure testing system.

In whole-engine testing, common pressure transmission methods are divided into three types: the Flush Method, 

the Finite-Length Tube Method, and the Semi-Infinite Tube Method.

(I) Flush Method

The Flush Method installs the pressure sensor's sensing surface flush with the inner wall of the test section, 

eliminating the need for pressure transmission tubes. This method offers the best dynamic performance; the sensor 

directly experiences the gas pressure, the path for pressure fluctuations to reach the sensor is short, and there is 

almost no time delay. However, the Flush Method lacks the heat dissipation provided by pressure transmission tubes,

 placing higher demands on the sensor's temperature resistance, making it unsuitable for high-temperature pressure 

testing.

(II) Finite-Length Tube Method

The Finite-Length Tube Method is suitable for high-temperature dynamic pressure testing. The pressure sensor is 

installed at the end of the pressure transmission tube, creating a path for pressure wave propagation. However, 

the enclosed cavity causes a time delay in pressure wave transmission, and reflections at the terminal end create 

standing waves, leading to waveform distortion and severely affecting the system's dynamic performance. To reduce 

the cavity standing wave effect, it is necessary to keep the tube length as short as possible and the inner diameter 

as large as possible.

(III) Semi-Infinite Tube Method

The Semi-Infinite Tube Method installs the pressure sensor on the side of the tube for measurement. 

When the tube is sufficiently long, the reflection of the pressure wave at the terminal end is attenuated by gas 

damping, causing the reflected wave to disappear quickly and avoiding standing waves. While ensuring heat 

dissipation, the Semi-Infinite Tube Method can prevent signal distortion from standing waves. However, this 

method involves a section of tubing, resulting in a more complex structure and greater design difficulty.

Currently, research on simple straight tubes and simple media pressure transmission tubes is mature, but further 

study is needed on dynamic characteristics under complex conditions and with complex media. Future efforts 

should focus on addressing the impact of dynamic characteristics of pressure transmission tubes under complex 

conditions, optimizing the structural design of semi-infinite tubes, and improving the accuracy and reliability of 

pressure testing.

Among the many brands of pressure scanners, the Gensors pressure scanner is equipped with highly sensitive 

silicon piezoresistive pressure sensors capable of accurately measuring both total and static pressure parameters. 

Its measurement accuracy can reach up to ±0.05% FS (Full Scale). This means that in aero-engine whole-engine 

testing, even minute pressure changes can be precisely captured, providing reliable data support for engine 

performance evaluation.

Gensors DAS-P16压力扫描阀系统介绍