Problem

When attempting to compute a transient simulation in HAMMER, it suddenly fails and reports "Calculation cancelled by user" even though the progress was never cancelled by the user.

Solution

This can occur if the transient solver encounters a situation that it cannot handle and does not have a validation message for. Here are some possible causes:

Too many pipes connected to nodes

There is an internal limit on the number of pipes that can connect to a given node in the transient solver. This issue has been known to occur if there are more than 16 pipes connected to a node. This can happen in some situations where duplicate overlapping pipes are connected that the user did not intend to connect. You can use the Network Navigator query "Duplicate Pipes" to locate all other instances of multiple pipes between nodes. You can use the highlight button to highlight all cases in blue and review each one and fix as needed. Unexpected overlapping pipes could have been due to issues with the data source if you built the model from a GIS (or updated it repeatedly).

This issue should be resolved in a future release (reference # 813897) so that an informational message is presented.

Too many air valves using air flow curves

If this happens when using the air flow curve method with air valves, you may have encountered a known issue (reference number 1356178 reported for HAMMER 23.00.00.19) related to the number of air valves using the custom air flow curves. In at least one case, this was known to occur when using 300+ air valves with air flow curves. Try using the orifice diameter method on some air valves or contact Support for help.

Report Times set to "At No Times"

This issue has been known to occur when certain element types are used in the model and that "Report Times" transient calculation option is set to "At No Times". Select "Periodically" or "At All Times" instead.

This issue should be resolved in a future release (reference # 813897) so that an informational message is presented.

See Also