MATHMET Dynamic

Analysis of dynamic measurements

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Dynamic Pressure

Applications

In-cylinder pressure: a key dynamic pressure application (AVL List GmbH)

There are many industrial applications in which the measurement of dynamic pressure is required.

Examples of such applications include:

Automotive engine development

Knowledge of the in-cylinder pressure throughout the combustion cycle enables the fuel injection and timing parameters to be optimised, to maximise efficiency and minimise emissions.

Turbomachines

Turbomachines, such as compressors, turbines, pumps, and fans, are important components in steam and gas turbines found in power plants and in aviation jet engines. To find sources of losses and to calculate the efficiency of turbomachines, the measurement of dynamic pressure is vital. In the engineering of turbine engines and rocket propulsion systems, dynamic pressure measurements are used for active control, thrust measurement, and overpressure indication.

Machine control

Hydraulic and pneumatic components, such as engines, pumps, transmissions, actuators, and valves, are often used to control the motion of industrial equipment. Measurement of the dynamic fluid pressure is often critical in developing these components and monitoring their performance.

Materials forming

Dynamic pressure measurements are performed in order to optimise production processes. Examples are injection moulding and extrusion performed in the plastics industry, as well as die-casting.

Blast waves and ballistics

A primary result of the detonation of explosives is the propagation of a pressure pulse known as a blast wave. The measurement of this dynamic pressure is important from two different points of view: firstly, those developing explosives want to achieve maximal and directed destructive capability and, secondly, those developing military and civilian shelters want to achieve constructions which withstand air blast and ground shock loading. Dynamic pressure is also measured when developing weapon systems such as guns, cannons, missiles, and ammunition.

Existing Standards

Few documentary standards on dynamic pressure calibration currently exist, at least in part due to the fact that there have been no national (non-acoustic) dynamic pressure standards available to provide traceability to the SI. The most applicable existing document is ISA‑37.16.01-2002, A Guide for the Dynamic Calibration of Pressure Transducers, published by ISA, the International Society of Automation.

Under the auspices of ISA, committee 107 (Advanced Instrumentation Techniques for Gas Turbine Engines) has been created to develop standards to ensure measurement accuracy in the operation of gas turbine engines, with subcommittee ISA 107.5 focusing on the measurement of dynamic pressures – this subcommittee is being driven by PIWG, the Propulsion Instrumentation Working Group.

Work is also underway within ISO/TC 108 – the International Organisation for Standardisation’s Technical Committee on Mechanical vibration, shock, and condition monitoring. Within this committee, Working Group 6 (Calibration of vibration and shock transducers) of Subcommittee 3 (Use and calibration of vibration and shock measuring instruments) is developing a standard covering the calibration of dynamic pressure measurement systems.