Micro-combustion modelling with RBF-FD: A high-order meshfree method for reactive flows in complex geometries

New micro-devices, such as unmanned aerial vehicles or micro-robots, have increased the demand of a new generation small-scale combustion power system that go beyond energy-density limitations batteries fuel cells. The characteristics short residence times and intense heat losses reduce efficiency combustion-based devices, key factor requires an acute modelling effort to understand competing physicochemical phenomena hamper their efficient operation. With this objective in mind, paper is devoted development high-order meshfree method model inside complex geometries using radial basis functions-generated finite differences (RBF-FD) based on polyharmonic splines (PHS) augmented with multivariate polynomials (PHS+poly). In our model, chamber micro-rotary engine simulated by unsteady reaction-diffusion equations coupled steady flow passing bidimensional stenotic channel great slenderness. conversion characterized identifying different regimes emerged function ignition point. We show PHS+poly RBF-FD able achieve algebraic convergence scattered node distributions, enabling for refinement regions fluid domain. This feature makes it specially well adapted integrate problems irregular front-like solutions, reactive fronts shock waves. Several numerical tests are carried out demonstrate accuracy effectiveness approach.