Numerical simulation of turbulent compressible flows in a C-D nozzle with different divergence angles

Compressible gas flow inside a convergent-divergent nozzle and its exhaust plume atdifferent nozzle pressure ratios (NPR) have been numerically studied with severalturbulence models. The numerical results reveal that, the SST k–ω model give the bestresults compared with other models in time and accuracy. The effect of changes in value ofdivergence half-angle (ε ) on the nozzle performance, thrust coefficient ( Cf ) anddischarge coefficient ( C d) has been investigated numerically. The predicted results showthat for a given divergence angle, the thrust coefficient (Cf ) increases by increasing nozzlepressure ratio. Also, for a given nozzle pressure ratio, the thrust coefficient increases as thenozzle divergence angle decreases. When the CD nozzle is chocking, the value of dischargecoefficient is independent of nozzle pressure ratio and also for a given nozzle pressure ratio,the discharge coefficient increases as the divergence nozzle angle (ε) increases.