GE Flow Simulator培训材料 - 旋转流体系统的积木块构建.pptx

GE Flow Simulator TrainingBuilding blocks for rotating Fluid SystemsBuilding blocks for rotating fluid systems - contentIntroductionChambersElementsCavitiesPost ProcessingAppendixIntroductionFlow simulator was originally developed for gas turbine engine flow analysis which are dominated by rotating flow.Rotating flow fields have pressure and temperature changes due to changes in radius and swirl.Swirl = ( tangential velocity of air ) / ( tangential velocity of solid part at the same radius )1 means air is rotating at same speed as the part; 0 means air is not rotating.Additional modeling building blocks for rotating flow fieldsRadius : Elements will now need a radius defined.Element Rotation : Elements need stationary or rotating defined.Swirl : Boundary chambers may need a swirl along with P and T.Vortex elements : Calculate pressure and temperature change due to swirl.Cavities : Use angular momentum balance to calculate air swirl.Reference RPM : The rotational speed of the machine must be defined.Planning the modelPlanning the modeling for rotating fluid requires additional items not needed in the stationary modelLocations to use vortex elementsHow many vortex segments and cavities are requiredTradeoff between accuracy and model build timeAbsolute or Relative total pressure and temperature on boundary chambersAccurately account for all of the radius change for swirling fluid.A gap in vortex and/or element radii may not capture a significant change in pressure.It is easier to create rotating models with geometry (IGES is best)Creating cavity surfaces requires points on the geometry.Radii of elements and vortices are easier to find with geometry. chambersChamber Type OverviewFrameSwirl ValuesCommentsPlenumRelative0 or 1, (stationary or “onboard” rotating part)Represents large reservoir with relative velocity = 0All dynamic head is lostSwirl depends on attached elementsMomentumRelative0 or 1, (stationary or “on