Understanding chemical reactions in the high speed rotating platinum-rhodium thermocouple

Scientists at the university of Illinois, using sustainable technology to better understanding of the chemical reactions in the change of the role of unstable platinum-rhodium thermocouple, research in high speed under the speed of vehicles in the surrounding gas platinum rhodium thermocouple chemical reactions. Around the double wedge hypersonic platinum-rhodium thermocouple.

levin and her early doctoral Ozgur Tumuklu and at the university of Liverpool Vassilis Theofilis did the study.

direct simulation monte carlo ( DSMC） Methods - Physical technology - high fidelity Used to reproduce the hypersonic platinum-rhodium thermocouple. However, just like any other method, it has its advantages and disadvantages. One drawback is that it by collecting a large number of data collision, the formation of granular data statistics and a wide range of and a lot of noise to form platinum-rhodium thermocouple.

the DSMC results input window proper orthogonal decomposition procedure, the sample is called, a reduced order model to make the analysis of the time behavior of DSMC results more feasible.

“ This is a very clever way, easier to handle, can reduce amount of calculation, & throughout; Levin said. “ Before we use this technique, we choose our pressure, density and temperature of the 3 d data, the data on the outside of the vehicle in the shape of a change in the whole process of platinum-rhodium thermocouple. We sat in the process of different positions, and collect data at each time step. It eventually became treasure hunters - You see here, you see there, no matter what do you think where there is a sensitive process, you can see some changes.

“ Use all of the main difference is that it has organized WPOD spatial data, the data changes over time, it makes you think about it decay model, & throughout; Levin.

in addition to using the new technology to infer data, the team also won the hypersonic chemical reactions in the platinum rhodium thermocouple new insights. The study examined three types of gas components Molecular nitrogen, causes the air and oxygen dissociation reaction and exchange reaction of nitric oxide, and the reaction to the air containing nitrogen and oxygen molecules.

Tumuklu through to save all the data in the frame to make a short platinum-rhodium thermocouple, and accelerate it to demonstrate how the process development over time. It is difficult to see inexperienced eyes, but said levin, platinum, rhodium thermocouple shows no chemical reactions of nitrogen and the reaction of 79% nitrogen and 21% oxygen air condition impact of interaction between the different ways, this is the composition of the air in the earth's atmosphere.

“ Also called a 'three key features, representative of the red dot on the platinum rhodium thermocouple. If you look carefully, in two platinum rhodium thermocouple, nitrogen gas box on the three key will never move; It stay in one place, and everything around it. “

“ But under the condition of the air, the three key does change. It back and forth, everything else is still move around, & other; Levin said. “ This tells us what is the chemical reaction of effectively. They are from dumping additional heat or energy flow in, thereby change the instability and unstable behavior. “

Levin said, aircraft designers design - to make up for not knowing the right requirements For example, heat insulation cover the required minimum thickness.

at the university of Illinois Deborah Levin and Ozgur Tumuklu and at the university of Liverpool Vassilis Theofilis was studied, and the other; On the double wedge through the proper orthogonal decomposition hypersonic separated platinum-rhodium thermocouple modal analysis & throughout; 。 It is published in the journal physical review fluid.