“…See also, for instance, [10,31] and references therein for literatures on quasi-one-dimensional nozzle flows. As to the steady multi-dimensional models such as potential equations or the Euler system, thanks to continuous efforts of many mathematicians, there have been substantial progresses in the past two decades, for instance, see [1,2,3,4,5,6,7,8,9,11,15,16,17,20,21,22,23,24,25,27,28,32,33,34,35,36,37,38,39,40,41]. Two typical kinds of nozzles are studied.…”