Evaporation and condensation characteristics of n-heptane and multi-component diesel droplets under typical spray relevant conditions

•Influence of fuel vapor concentration and compositions on the droplet behaviors at typical spray relevant conditions.•Numerical model incorporated with the real vapor-liquid thermodynamic equilibrium and multi-component diffusion coefficients.•Two thresholds determining the condensation occurrence and approximately stable state.•Pressure effect on the droplet evolutions not only depends on the ambient temperature but also the vapor concentration.