Spark ignition phenomena have been studied from various viewpoints in the context of premixed flames. Relatively little has been done on the spark ignition in the context of non-premixed combustion. Spark ignition of inhomogeneous gaseous or gas-droplet mixtures has applications in aviation gas turbine relight and direct injection engines. We explore the fundamentals of ignition processes by experiments and Direct Numerical Simulations (DNS). Modelling of this process is also carried out with the Conditional Moment Closure (CMC) in the context of Reynolds Averaged Navier Stokes (RANS) simulation.