Measurements of explosion parameters for diethyl ether/air mixtures at pre-ignition quasi-isotropic turbulence

摘要

This paper presents a detailed investigation of the explosion characteristics (i.e., maximum explosion pressure, maximum rate of the pressure rise) and combustion properties (i.e., laminar burning velocity, turbulent burning velocity) of diethyl ether (DEE)/air mixtures under different pre-ignition quasi-isotropic turbulence velocity. The concentration of DEE/air mixtures is the equivalence ratio ?= -1.1. The experiment is performed by systematically measuring the pressure evolutions in a 20-L explosion spherical vessel. The present measurement shows that the peak explosion pressure (Pmax) increased nonlinearly with increasing pre-ignition turbulence velocity. The peak pressures reach the maximum values of 0.93 MPa at pre-ignition turbulence velocity 6.2 m/s, and the lowest are 0.57 MPa at pre-ignition turbulence velocity 1.0 m/s. The experimental result of the laminar burning velocity (uL) is - 0.55 m/s, and the largest data of turbulent burning velocity (ut) are 1.8 m/s at pre-ignition turbulence velocity at 6.2 m/s. In this work, the model gives the expression on the laminar burning velocity (uL) and turbulent burning velocity (ut) versus the pre-ignition turbulence velocity Urms in accordance with Williams?s theoretical model.