We present a new algorithm for simulating two-fluid gas and dust mixtures in Smoothed Particle Hydrodynamics (SPH), systematically addressing a number of key issues including the generalised SPH density estimate in multi-fluid systems, the consistent treatment of variable smoothing length terms, finite particle size, time step stability, thermal coupling terms and the choice of kernel and smoot...

I was surprised to see that Philip Anderson’s obituary (Physics Today, June 2020, page 59) did not mention how he viewed the belief held by some in particle physics their field deserves more funding than other areas. Anderson had said, “There is a great arrogance and immodesty about whole field.” The sidelining of disciplines preference contemporary, exotic fields, especially when it comes awar...

A simple variational calculation is presented showing that a uniformly rotating barotropic fluid in an external potential attains a true energy minimum if and only if the rotation profile is everywhere subsonic. If regions of supersonic rotation are present, fluid variations exist that could take the sytem to states of lower energy. In any given system, these states may or may not be dynamicall...

A novel computational fluid dynamics and molecular kinetic theory (CFD-MK) method was developed to simulate the impingement of a nanodroplet onto a solid surface. A numerical solution of the Navier–Stokes equation using a volume-of-fluid (VOF) technique was used to model nanodroplet deformation. Dynamic contact angle during droplet impact was obtained by molecular kinetic theory. This dynamic c...