Flownex® SE 2019 is pushing the boundaries of thermal fluid system simulation.
We’ve added a few new enhancements and additions, including improvements to our heat exchangers, a custom vortex as well as a whole new appearance and functionalities to our graphs. We’ve also updated a few of our components to allow liquid-gas mixture fluid types.
A NEW student version 2019 is also available to download.
The inputs of the Rotor-Rotor and Rotor-Stator components have been significantly enhanced in order to allow a user to easily specify a complex geometry for the cavity.
The complex geometry can be specified by using the Cavity Editor, which opens when double clicking on a Rotor-Rotor or Rotor-Stator component. The Cavity Editor allows the user to import a background picture for the cavity. The geometry and dimensions can then be defined on the picture in the Cavity Editor, as seen in Figure 2.
After a picture has been imported, the user can define the dimensions of the cavity by specifying two points at any location on the drawing. Thereafter, the rotor and stator surface geometries are easily drawn on top of the picture.
Other geometric items like the position of bolts, gap and shroud width, as well as defining the discretization is also done easily using this Cavity Editor.
New icons have been added for the Shell and Tube heat exchanger and the names now clearly indicate the shell side and the tube side.
The shell side supports specification of the friction factor through a constant value, using a script or using a Fanning friction chart. By default, the Fanning friction factor chart is used. The user can however easily use a correlation from another source in the script defined friction factor specification. These options can be seen in Figure 8.
The shell side now supports built in correlations for the heat transfer coefficient calculation, as well as script defined heat transfer coefficient calculation, constant value specification and Stanton Prandtl charts. By default, the Shell Side heat transfer coefficient calculation correlation is used. The user can however easily use a correlation from another source in the script defined heat transfer coefficient calculation, as seen in Figure 9.
The tube side supports specification of the friction factor through a constant value, Darcy Weisbach correlations, using a script or using a Fanning friction factor chart. By default, the Darcy Weisbach correlation is used, as seen in Figure 10.
The tube side supports built in correlations for the heat transfer coefficient calculation, as well as script defined heat transfer coefficient calculation, constant value specification and Stanton Prandtl charts, as seen in Figure 11. By default, the Gnielinski correlation is used for the tube side heat transfer coefficient calculation.
New icons have been added for the Finned Tube heat exchanger and the names now clearly indicate the fin side and the tube side.
Fin Side Geometry
A simplified set of inputs has been added to specify the geometry of a rectangular finned tube heat exchanger with round fins. This is the default option now, as seen in Figure 13.
The user now specifies more readily available geometric parameters like the heat exchanger width height and length as well as tube and fin diameters. The older more generic specification is still available.
Fin Side Primary Loss Calculation
The fin side supports specification of the friction factor through a constant value, using a script or using a Fanning friction factor chart. By default, the Fanning friction chart is used. The user can however easily use a correlation from another source in the script defined friction factor specification.
Fin Side Heat Transfer Coefficient Calculation
The shell side now supports script defined heat transfer coefficient calculation, constant value specification and Stanton Prandtl charts. By default, Stanton Prandtl chart is used. The user can however easily use a correlation from another source in the script defined heat transfer coefficient calculation.
Tube Side Primary Loss Calculation
The tube side supports specification of the friction factor through a constant value, Darcy Weisbach correlations, using a script or using a Fanning friction factor chart. By default, the Darcy Weisbach correlation is used.
Tube Side Heat Transfer Coefficient Calculation
The tube side supports built in correlations for the heat transfer coefficient calculation, as well as script defined heat transfer coefficient calculation, constant value specification and Stanton Prandtl charts. By default, the Gnielinski correlation is used for the tube side heat transfer coefficient calculation.
The Recuperator heat exchanger has been renamed to the Plate Heat Exchanger, which describes the functionality of the heat exchanger better. New icons have been added for this heat exchanger too.
Primary & Secondary Side Primary Loss Calculations
Both sides support specification of the friction factor through a constant value, Darcy Weisbach correlations, using a script or using a Fanning friction factor chart. By default, the Darcy Weisbach correlation is used with the addition of friction factor multipliers that can be used in the laminar and turbulent ranges to adjust the friction factor.
Primary & Secondary Side Heat Transfer Coefficient Calculation
Both sides support built in correlations for the heat transfer coefficient calculation, as well as script defined heat transfer coefficient calculation, constant value specification and Stanton Prandtl charts. By default, the Gnielinski correlation is used for the tube side heat transfer coefficient calculation.
The graphs inputs have been modified such that only basic graph properties are shown when creating a new graph to ease formatting/styling. Additional formatting properties are available when checking the Advanced Formatting properties, as seen in Figure 15.
New graph functionalities include:
The Daily and Nece correlation for calculating moment coefficients on disk surfaces was added as an option for the Rotor-Stator and Rotor-Rotor cavities as seen in Figure 16.
In the case of the Rotor-Stator cavity, the Daily and Nece correlation allows for four different regimes, including fully interfering boundary layers within very small gap widths. The possibility to modify the Haaser et. al. correlation to be dependent on the gap width to disk diameter ratio was also added.
The Rotor-Stator and Rotor-Rotor cavities were upgraded to allow specifying an inner radius and outer radius for each disk individually, this is specifically useful when modelling cavities with axial inflows/outflows.
The Rotor-Stator and Rotor-Rotor cavities were upgraded to allow a disk surface profile specification that is not strictly rising with radius.
An option was added to all elements connected to vortices and cavities to specify the radius at the connection rather than the radius fraction. This allows the user to easily link the connection radius input to a measurement on a scaled drawing.
An increment result for windage power was added to the Rotor-Stator and Rotor-Rotor cavities. The windage power calculation of the Rotating Channel, Rotating Nozzle, Labyrinth Seal and Rotating Annular Gap was modified to automatically account for windage addition/removal to the element on account of upstream node swirl speeds not equal to that inside the element. Previously the windage power added to these elements was solely attributed to that required to maintain the swirl speed inside the element. This modification may lead to modified results since windage affects gas density.
The windage power calculation on the Forced Vortex component was modified to account for changes in kinetic energy of incoming flow streams that must increase/decrease in order to be equal to the swirl speed of the vortex at the particular connection radius. This modification may lead to modified results since windage affects gas density.
The following components were extended to allow liquid-gas mixture fluid types, thereby allowing coupling of the secondary air system with the lubrication system:
The combustion category has been renamed to Chemical Reactions. The existing Adiabatic Flame model is a chemical reaction where the end temperature and composition of the end product of the reaction is determined by the CEA calculations. Another component has been added to the Chemical Reactions library where the user can specify the end temperature of the chemical reaction, namely the Gibbs Free Energy Reactor.
The setup of measurements in scale drawings has been simplified. The user can now drag and drop properties from components onto measurement points and measurement lines.
If it is a measurement point, the user will be asked to which part of the coordinate (X,Y, or Z) it should be assigned.
If the user drags and drops on a line, the property will automatically be associated with the length of the line.
Errors when using a comma as decimal separator were fixed. The interface is able to handle both a point or a comma as decimal separator.
The option was added to deactivate the simulation when the CFX Generic Interface encounters an error. A user can continue the simulation from the point where the error (can include CFX solver crash) occurred, saving the time it took to reach that point.
In the past, the AFT importer always searched for a scenario named Base Scenario or Base Case to import. This has been improved and the first scenario listed in the Scenario Manager section of the file will now be imported. This enhancement fixes issues were scenarios did not have the default Base names.
Functions were added to the network builder to set the page size for any page.
The Ansys mechanical link now allows a user to specify the name of boundary conditions to transfer load data. Specifying the same names for matching boundary conditions and named selections allows the user to use named selections in the link setup.
The unit g/mol was added for molar mass.
The unit kN was added for force.
Correlations for calculating convection heat transfer to ambient was added to the Composite Heat Transfer component, as well as the Insulated Pipe component.
Correlations for three different convection mechanisms were added, namely free convection over a horizontal cylinder, free convection over a vertical cylinder, or forced convection over a cylinder. The user can select the mechanism that should be used, as seen in Figure 22.
Added Wall Shear Stress result for Pipe elements with Newtonian Fluids.
Added warnings for low and high limits when interpolating from two-phase tables. Added warning when two-phase critical mass flux cannot be calculated due to low total pressure.
Improved the checking and issuing of errors for materials in the Advanced Reactor – materials that did not exist issued warnings even when options were active where they were not used.
Several improvements were made to the text based Nuclear results. This includes correcting the generated heat results for solid nodes and solid node volume results. Also, units were added and corrected for heat in several places.
Added an energy source result on solid nodes, as well as transient energy source calculation on all node types. A Gibbs free energy result was also added to flow nodes.
The Container Interface Top and Container Interface Bottom components were enhanced to allow the specification of height or height fractions on adjacent elements. Previously, elements could only be connected at the bottom or top.
