Device and method for measuring engine combustion flow field speed based on molecular absorption spectrum

Abstract

The invention provides a device and a method for measuring engine combustion flow field speed based on molecular absorption spectrum. The measuring device comprises a laser setting unit, a laser beam-splitting unit, a measuring unit, a data acquiring system and a data processing unit, wherein the laser beam-splitting unit and the laser setting unit are connected and positioned at one side of an engine combustion flow field; the measuring unit comprises two laser detectors which are positioned at the other side of the engine combustion flow field and opposite to the laser beam-splitting unit; the data processing unit is used for processing data stored in the data acquiring system to obtain the fuel flow field speed. Based on the molecular absorption spectrum, a laser decaying pulse signal caused by fuel gas component concentration changes is used as a cross-correlation analysis random signal to realize cross-correlation speed measurement, so that the device and the method for measuring engine combustion flow field speed based on molecular absorption spectrum provided by the invention can obtain relevant data by only needing to enable laser to pass through a to-be-tested combustion flow field. The device has the advantages of a simple structure, a non-contact type and high sensitivity.

Description

technical field [0001] The invention belongs to the field of flow field velocity measurement, in particular to a device and method for measuring engine combustion flow field velocity based on molecular absorption spectrum. Background technique [0002] In the combustion flow field of engines such as aero-engines and rocket engines that use hydrocarbons as fuel, the velocity of the flow field is one of the important parameters to analyze the combustion state and evaluate the performance of the engine. However, due to the high flow field velocity and air temperature, and the complexity of combustion, multiphase flow, heat transfer and mass transfer process, it brings many difficulties to the measurement. [0003] At present, the commonly used measurement methods for engine combustion flow field velocity are intrusive measurement method and image measurement method. The intrusive measurement method places the test part in the flow field, which not only easily disturbs the flow...

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Problems solved by technology

The intrusive measurement method places the test part in the flow field, which not only easily disturbs the flow field, but even causes the change of the flow field, and the results usually need to be further corrected, and the accuracy is not high; the image measurement method usually needs to add tracer particles to the flow field , but for the engine combustion flow field, it is difficult to add tracer particles evenly in the flow field, and the tracer particle image is easily obliterated by the strong combustion flame signal, and the tracer particles will also affect the combustion

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