Slide 1

IntroductionTruncated nozzle designed for PR=1030 with 87.72in length. Unstructured grids with 1,80,000 cells.No inflation at wall boundaries.RNG K-e turbulence model is used with enhanced wall treatment.Investigated and compared for two casesChen Nozzle contour(from coordinates)MOC contour for same design conditions.Investigated for two cases (BC at edges):Pressure Far-field Pressure-outlet

Chen geometry@5bar-PFConvergedNet mass flow rate =0.8190kg/sQualitatively acceptable

Chen geometry@10bar-PFIssuesAbsolute pressure limited to 1e0 PaTemp. limited to 1e0kIncorrect Physical results

K-e chen@5bar-POReversed flow is observed.

MOC@5bar-PFIssuesAbsolute pressure limited to 1e0 PaTemp. limited to 1e0kIncorrect Physical resultsTime step reduced due to excessive temp changes

MOC@5bar-POQualitatively acceptibleObserved for only 5000 iterations.Residuals are observed to be still decreasing.Net mdot = -499.323kg/s.(PO)

MOC@15bar-POReversed flow is observed at PO boundaries.Net mdot =-623.11kg/sResiduals-almost constant

MOC@25bar-POReversed flow is observed at PO boundaries.Net mdot =-1750.1653kg/sResiduals-almost constantStill iterations has to be done