==== AFT Impulse 4.0 (Version Date 2008.05.01) Release Notes ===== This file contains the changes that have been made to Impulse 4.0 *** Changes for Version Date 2007.10.12 *** None: Initial Release *** Changes for Version Date 2007.10.19 *** >> Changes to computation logic that could impact results << 1. None. >> Changes to data management that could impact results << 1. None. >> Changes that do not impact results << 1. With international Windows settings sometimes the font size in the Visual Report window is unrealistically large (greater than 100 for example). Now any font size greater than 50 is set to 12. 2. The new Vacuum Breaker Valve three-stage option was not enabled for user selection. Now it is enabled. 3. Increased size of information text on Output, Graph Results and Visual Report window. 4. Fixed problem with models that have a large number of closed pipes and junctions taking an extremely long time to load a scenario. *** Changes for Version Date 2007.10.22 *** >> Changes to computation logic that could impact results << 1. None. >> Changes to data management that could impact results << 1. There was a problem with the Pump Specifications window that caused the data from an existing pump junction to be lost when the window was opened. The pump was saved OK once it was defined but could not be edited without entering the data again. This was fixed. >> Changes that do not impact results << 1. The surge tank junction accepted connecting pipes at a different elevation than the junction. This feature was not intended to model uncovered pipes when tanks drain, but it was possible that it might be interpreted that way. So the feature was removed. 2. The Graph Results feature to not show the legend was not working properly. This was fixed. *** Changes for Version Date 2007.11.27 *** >> Changes to computation logic that could impact results << 1. A fixed flow pump that was off during steady-state and had a startup flowrate transient would never start. This was fixed. The controlled pump flow (and controlled pressure) worked fine. This change only affected fixed flow pumps with transients. 2. Fixed problem with submerged pumps that have special conditions being open with flow through that also use an internal check valve that is closed during the initial steady state part. The check valve was ignored and the pressure values were being propagated through the pump which caused an artificial transient. >> Changes to data management that could impact results << 1. None. >> Changes that do not impact results << 1. Fixed erratic toolbar and menu behavior on Workspace. 2. Fixed problem where the Pipe Fittings & Losses were not printing in Model Data. 3. Fixed problem that caused long delays when multiple pipes and junctions were deselected on the Workspace. *** Changes for Version Date 2007.12.31 *** >> Changes to computation logic that could impact results << 1. Changed transient tee resistance calculations by adding a lower flow ratio cutoff to avoid extremely low flow ratios which can cause unstable and inaccurate results. 2. Fixed steady-state tee calculation problem when there was a negative K factor and negative flow. Impulse could converge on a result which was poor. >> Changes to data management that could impact results << 1. The time setting was not being cleared when a pump transient model was reset to None. This caused incorrect units to be passes when the trip time was being converted. Opening the Pump Specifications window again and clicking OK would reset this. 2. There was a serious problem with Transient Control that could affect international users that was fixed. The problems relates to the international use of the "," symbol as a decimal separator. A new parameter in Transient Control is the Psi weighting factor which was supposed to be between 0 and 1, but a value of 0.5 (or 0,5 internationally) was being interpreted as "5". This was fixed and also checks were included to keep the value always within 0 and 1. >> Changes that do not impact results << 1. The Checklist has a button to open the relevant window and the tooltips were not correct. These were fixed. 2. In Transient Control added persistent drop down symbols to the Pipe Station Output grid. 3. Assigned Flow junction was not properly saving the option for transient flow type (absolute vs. relative). This was fixed. 4. Fixed Workspace Undo problem when trying to undo the stretching of a single pipe. *** Changes for Version Date 2008.01.15 *** >> Changes to computation logic that could impact results << 1. When using a relief valve which has two pipes and exits directly to an external pressure, and when the constant Cv or K model was used, the values for the adjacent pipes were not updated by the solver and hence were never correct once the valve opened. This would affect all results that occurred after that point. This was fixed. >> Changes to data management that could impact results << 1. Fixed problem when an fixed loss value was entered directly in the Pipe Specifications Window when the regional settings used a comma as a decimal separator. The Fittings and Losses window was not affected. >> Changes that do not impact results << 1. When one moves a junction which has connected pipes, and the pipes are not moved at the same time as the junction, then when one undoes the move and then redoes it, the redo would not work properly. This was fixed. 2. Fixed problem when a junction was morphed when there were no changes in any child scenarios. *** Changes for Version Date 2008.01.17 *** >> Changes to computation logic that could impact results << 1. Fixed a problem which was amplified by a change made in the 2007.12.31 version related to detailed tees. The problem exhibited itself when pipes connected to a particular tee had reference flow directions opposite of the physical flow direction. The tee calculation routine should have taken absolute values when getting flow split ratios but it did not. This has now been fixed. 2. Fixed a problem created in the 2007.12.31 version which caused flow imbalances in models with fixed or known flows in branching areas. The flows were overwritten with initial guesses and never changed. >> Changes to data management that could impact results << 1. None. >> Changes that do not impact results << 1. Changed how the Solution Balance Summary reports steady-state mass balance. Before it tried to always sum junctions to zero and show imbalances in the In/Out field. Now the In/Out field will only display for branch junctions with a flow source. And the total flow for junctions like reservoirs will show an imbalance because reservoirs are imbalanced by their nature. *** Changes for Version Date 2008.03.21 *** >> Changes to computation logic that could impact results << 1. When modeling a single pump with interpolated pump data and specifying it as one of a series of pumps on the Options tab, Impulse would give an artificial transient warning and stop. In some cases the artificial transient was real, and in other cases it was a false warning. Cases where it was real was when there was no transient on that pump, or there was a transient using the without inertia model, the pump trip with no backflow model, or the pump startup with no backflow model. All of the four quadrant models had warnings which were false. For the cases with real correct warnings Impulse was not accounting for the series pump setting and only modeled a single pump. The resulting artificial transient stopped the solver. Hence the user never saw any incorrect results. This was fixed. 2. Fixed problem with Detailed Tees/Wyes that would cause the transient solver to not complete the run. This was introduced in the 2008.01.17 version. 3. Fixed a problem where the losses for a detailed tee/wye that had flow coming in the branch and going out both straight-through pipes (or the opposite flow directions) were being set to zero. This was introduced in the 2008.01.17 version. 4. Momentum term for point force nodes was not being calculated correctly because the value for fluid density was not being set. >> Changes to data management that could impact results << 1. For Assigned Flow and Assigned Pressure junctions the setting for Infinite Pipe transient special condition was not being applied unless transient data existed. This was fixed. 2. When reading in models from Impulse 2 it was possible for the pointers to the output data to become corrupted. Once this happened, Impulse could not properly read output even if the model was rerun in Impulse 4. This was fixed. 3. Fixed problem with importing AFT Fathom files with Elbows, Heat Exchangers, Orifices Screens and Venturi. They were being converted to lossless Branches. They are now changed to General Components with the original loss value. 4. Fixed problem combining pipes that have additional losses. The loss types were not being combined properly. 5. Fixed a problem with force sets having the same ID. This occurred when the Transient Control was opened with existing force sets and a new one was added. >> Changes that do not impact results << 1. Fixed snap to grid problem when pipes or junctions were near an edge. 2. Fixed Workspace drawing anomaly when pressing the escape key while drawing a new pipe. 3. When in the Branch Specifications window, the F5 jump to next specifications window option did jump but did not close the Branch Specifications window which made it appear like it was not jumping. This was fixed. 4. Was not displaying pulp and paper stock properties when using constant properties in System Properties. Fixed this. 5. Added millibars (mbar) as unit of pressure 6. Fixed problem during transient run where a pump speed goes to zero and an error occurs. In some cases Impulse was dividing through by the zero speed to obtain a torque causing a divide by zero error. This was fixed. 7. Fixed problem printing the Model Data. An error would occur if there were no Fittings & Losses in the model. 8. Fixed problem reading in pumps from Impulse 2.0 files. 9. Allowed empty database files to be the target file in Database Manager. 10. Fixed problem displaying "Pipes and Junctions Only" in Model Data. 11. Fixed problem with the wavespeed being shown as defined when it had no value set. 12. Fixed problem printing the Visual Report legend units in Transient mode. 13. Made modifications to the estimated run time calculations. *** Changes for Version Date 2008.04.18 *** >> Changes to computation logic that could impact results << 1. During the transient a flow control valve which was closed by the user does not calculate correctly and gives erroneous results. This was fixed. 2. Fixed a problem where a valve would not open if connected to a partially full pipe. >> Changes to data management that could impact results << 1. Fixed problem in Global Junction Editing where if only the database name was selected, the data was not applied, only the name which caused inconsistent data. >> Changes that do not impact results << 1. Fixed printing problem for Graph Results which could cutoff part of a graph in certain cases. 2. Allowed empty database files to be the target file in Database Manager. 3. Fixed problem where the model data setting for pipes would not be set as the user default unless the Model Data Control window was first closed and reopened. 4. Fixed a problem in the Fittings & Losses database the use of a comma in the type or subtype name would cause the data to become corrupted. 5. Added more information explaining what happened when a valid license was not found. *** Changes for Version Date 2008.05.01 *** >> Changes to computation logic that could impact results << a. None. >> Changes to data management that could impact results << a. A check valve with transient data would have the data truncated when a scenario was created or when an Impulse 3.0 model was read in. This was fixed. >> Changes that do not impact results << a. Fixed for data field anomaly in pump specifications window when that occurred sometimes when the "No Transient - Four Quadrant method is chosen.