Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Rankine Hugoniot conditions, also referred to as Rankine Hugoniot jump conditions or Rankine Hugoniot relations, relate to the behaviour of shock waves traveling normal to the prevailing flow. They are named in recognition of the work carried out by Scottish engineer and physicist William John Macquorn Rankine and French engineer Pierre Henri Hugoniot. See also Salas (2006) for some historical background.Consider a one-dimensional, calorically ideal gas described by a polytropic equation-of-state and operating under adiabatic conditions. In addition, assume that the fluid is inviscid (negligible viscosity effects). Such a system can be described by the following system of conservation laws, known as the 1D Euler equations.