Semnan University PressJournal of Heat and Mass Transfer Research2345-508X1220141001Numerical simulation of turbulent compressible flows in a C-D nozzle with different divergence angles9310018410.22075/jhmtr.2014.184ENMohammad HadiHamedi EstakhrsarMalek-Ashtar University of Technology, Tehran, Iran.MehdiJahromiMalek-Ashtar University of Technology, Tehran, IranJournal Article20131212Compressible gas flow inside a convergent-divergent nozzle and its exhaust plume at<br />different nozzle pressure ratios (NPR) have been numerically studied with several<br />turbulence models. The numerical results reveal that, the SST k–ω model give the best<br />results compared with other models in time and accuracy. The effect of changes in value of<br />divergence half-angle (ε ) on the nozzle performance, thrust coefficient ( <em>C</em><sub>f</sub> ) and<br />discharge coefficient (<em> C</em> <sub>d</sub>) has been investigated numerically. The predicted results show<br />that for a given divergence angle, the thrust coefficient (<em>C<sub>f</sub></em> ) increases by increasing nozzle<br />pressure ratio. Also, for a given nozzle pressure ratio, the thrust coefficient increases as the<br />nozzle divergence angle decreases. When the CD nozzle is chocking, the value of discharge<br />coefficient is independent of nozzle pressure ratio and also for a given nozzle pressure ratio,<br />the discharge coefficient increases as the divergence nozzle angle (ε) increases.https://jhmtr.semnan.ac.ir/article_184_307e64ccb3b05405719a0be38a3d6895.pdf