Numerical study on laminar flame velocity of hydrogen-air combustion under water spray effects

In the context of hydrogen safety and explosions in hydrogen-oxygen systems, numerical simulations of laminar, premixed, hydrogen/air flames propagating freely into a spray of liquid water are carried out. The effects on the flame velocity of hydrogen/air flames of droplet size, liquid-water volume fraction, and mixture composition are numerically investigated. In particular, an effective reduction of the flame velocity is shown to occur through the influence of water spray. To complement and extend the numerical results and the only scarcely available experimental results, a “Laminar Flame Velocity under Droplet Evaporation Model” (LVDEM) based on an energy balance of the overall spray-flame system is developed and proposed. It is shown that the estimation of laminar flame velocities obtained using the LVDEM model generally agrees well with the experimental and numerical data. •Application of sprays for mitigation of Hydrogen explosion effects involving deflagration waves.•Development of a new predictive model for hydrogen/air laminar flame in presence of water droplets.•Physical analysis of the main factors influencing laminar flame velocity interacting with water droplets.•Validation of the model using available experimental and numerical data.