Causal Analysis of Flow Physics Using Transfer Entropy

It has become difficult to clarify the mechanism of complicated flowfield deductively, and the analysis of causal relation by inductive data-driven method is getting attention. Using one of such techniques called clustering transfer entropy, combustion instability in Continuously Variable Resonant Combustor (CVRC) was analyzed as a representative for a complicated but industrially and scientifically important flowfield. The mechanism of increasing longitudinal pressure oscillation by changing the oxidizer temperature was shown through deductive analysis. Based on the knowledge obtained deductively, the causal relationship between physical quantities in the fields was analyzed by the clustering transfer entropy. Physically consistent causal relationships between fuel and oxidizer flowfield are extracted. The causality from heat release rate to pressure was also consistent with the previous study.