This paper describes the design and development of Mach
3.6 water cooled facility nozzle using both analytical
and computational approaches and highlights the subsequent
experimental tests which showed that the results were
in agreement with the design intent. The nozzle has been
designed based on method of characteristics to get uniform
Mach number at the exit plane. Nozzle operating conditions
are 25 bar total pressure, 1700 K total temperature and
30 kg/s total mass flow rate with an exit area of 350 mm x
350 mm. In addition to the above effort, computational studies were made to predict and validate the flow in the Mach 3.6 nozzle that was designed to produce a uniform
supersonic flow. ANSYS-Fluent commercial code was used to
compute the flow through a 2-Dimensional convergent
divergent nozzle. The geometry and grid were generated using
the pre-processor (GAMBIT). In order to capture the boundary
layer efficiently, fine grid was generated near the wall.
The conservation equations were discretized with 2nd
order upwind scheme. Three different mesh sizes were
taken for the grid independence study and five different turbulence models were used for assessing the appropriate model. 2-D steady state RANS (Reynolds Averaged Navier-Stokes) equations were used for computation. Among
the models investigated, SST k- and RNGk- turbulence
models were found to give better agreement.