Research On Nozzle Plume Temperature Distribution Measurement System

For the most commonly use of rocket propulsion system,the temperature, flow, speed of its flame are fundamental parameters in denoting the combustion status of rocket engine, which has a direct impact on the design of weapon launching platform and the way to achieve it. The plume temperature of the rocket nozzle should be taken into consideration in the vector control of various missile weapons. According to the demands of the No.41 research institute of Hexi Chemical Engineering and Machinery Company, the Institute of Automatic Detecting and Process Control System (D&CS) of Harbin Institute of Technology has taken on the development of "the measuring equipment of nozzle plume temperature". Developing the research on nozzle plume temperature measurement system of solid propellant rocket engine (SPRE) has a practical significance on promoting the progress of rocket secreting technology and improving the devising level of weaponry of our country.The flame of SPRE has characteristics as fast flow, high temperature, short continuance ect. The method, introduced in this dissertation, which is used to achieve temperature measurement of the flame of SPRE is multi-spectral radiation thermometry, which has an unparalleled advantage over other emissivity compensating methods and may gain the emissivity and temperature of the object without any other additional methods.The main work contains the design and debug of hardware system and software system, the calibration of the pyrometer and the acceptance tests. The hardware system can be divided into two parts: the optical channel and the circuit. The radiant energy sent by the target is sampled by lens, transmitted through fiber, dispersed by prism and then reaches the photodetector, where it is transformed into electrical signal. The signal transits preamp, sample-and-hold amplifier and is collected by data acquisition card NI PCI-6225. The acquired data will be stored and processed in computer. The software is programmed by LabVIEW based on graphic language. It is easy to learn and can make program development faster. Calibration includes two sides: pyrometer wavelength function (PWF) calibration and temperature calibration.This system differs from the past similar equipment in many ways. It contains six pyrometers which can measure the temperature of any six targets in space. Using near-axis design and prism dispersal in optical channels to reduce the energy loss. Those channels are independent with each other, so there is no spectrum aliasing phenomenon. Data acquisition system that includes high-precision card NI PCI-6225, which integrated with 16-bit ADC, works steadily and has a strong anti-interference capability that makes great improvement to the system in speed and precision. The software is programmed by LabVIEW, which make hardware drive perfect and the data-processing much powerful.