The focus of this book is on the numerical aspects of large-eddy simulation of low-Mach number flows, where the convective speed of the flow is low but the variations of density is high, as a results of high temperature difference, which can be due to either heat transfer from the boundaries or combustion. An implicit time accurate approach combined with multigrid, residual smoothing, and preconditioning is used to increase the computational efficiency of a compressible solver at low-Mach regime. In the second part of the book, large-eddy simulation of particle-laden flow is considered. Lycopodium, glass, and copper particles with different diamters have been tested and the results are compared with the available data in the literature.