The deflagration-to-detonation transition via the interaction of a weak shock with series discrete laminar flames is analyzed computationally based on unsteady reactive Navier–Stokes equations one-step Arrhenius chemistry. For comparison, simulations Euler are also performed. numerical setup aims to mimic an array ignited at different spark times, artificially inducing chemical activity stimula...

Numerical simulations are performed to study the mechanism of deflagration detonation transition (DDT) in a pre-/main-chamber combustion system with stoichiometric ethylene–oxygen mixture. A Godunov algorithm, fifth-order space, and third-order time, is used solve fully compressible Navier–Stokes equations on dynamically adapting mesh. single-step, calibrated chemical diffusive model described ...

We present here a three-fluid three-pressure model to describe three-field patterns or three-phase flows. The basic ideas rely on the counterpart of the two-fluid two-pressure model which has been introduced in the DDT (deflagration to detonation theory) framework, and has been more recently extended to liquid–vapour simulations. We first show that the system is hyperbolic without any constrain...

In this work, to promote deflagration detonation transition (DDT), a designed hot jet in pre-detonator is produced initiate detonations the main tube. We perform two-dimensional simulations of DDT process for low-volatile fuel (n-decane) mixed with nitrogen and oxygen based on Eulerian–Lagrangian approach. The effects atomization, vaporization, shock focusing flame acceleration are discussed un...

We studied the mechanisms of flame acceleration (FA) and deflagration to detonation transition (DDT) triggered by a combination solid jet obstacles. The Navier–Stokes equations with detailed hydrogen–air kinetics model were utilized. Vast Kelvin–Helmholtz instabilities generate intensive turbulence–flame interactions, leading an increase in surface area high propagation velocity. position has s...

In the framework of the Chandrasekhar-mass deflagration model for Type Ia supernovae (SNe Ia), a persisting free parameter is the initial morphology of the flame front, which is linked to the ignition process in the progenitor white dwarf. Previous analytical models indicate that the thermal runaway is driven by temperature perturbations (“bubbles”) that develop in the white dwarf’s convective ...

In the present study, a discontinuous Galerkin (DG) framework is developed to simulate chemically reacting flows. The algorithm combines a double-flux method to account for variable thermodynamic properties, a Strang-splitting scheme for the stiff reaction chemistry, a robust WENO-based shock limiter, and the non-linear viscous-diffusive transport is discretized using the BR2 method. The algori...

We study the velocity of bubble walls in the electroweak phase transition. For several extensions of the Standard Model, we estimate the friction and calculate the wall velocity, taking into account the hydrodynamics. We find that deflagrations are generally more likely than detonations. Nevertheless, for models with extra bosons, which give a strongly first-order phase transition, the deflagra...