TimeStepping Class

Class specifying how timestepping is taking place.

Definition

Namespace: DHI.Mike1D.HDParameterDataAccess
Assembly: DHI.Mike1D.HDParameterDataAccess (in DHI.Mike1D.HDParameterDataAccess.dll) Version: 24.0.0.0 (11.1.1.1111)
C#
public class TimeStepping
Inheritance
Object    TimeStepping

Constructors

TimeSteppingInitializes a new instance of the TimeStepping class

Properties

AdaptiveSafeFactor When evaluating the optimal time step size for the next time step, this factor is multiplied on the estimated optimal time step.

1.0 is not optimal, because then too many time steps fail. Tests has indicated values between 0.95 and 0.99 to be optimal for M11 type setups and between 0.8 and 0.9 for MU type setups.

Default value is 0.9

BoundaryMaxRelativeChange Maximum acceptable relative change of boundary value, Adaptive Time Stepping |resid(BC)/BC| Also called "dDelB_BVal".
BoundaryMaxRelativeChangeLimit Adaptive Time Stepping |resid(BC)/BC|. For boundary values less than this, the boundary check is not performed.

Also called "dDelB_BLim"

CourantADMax Adaptive Time Stepping Courant AD
CourantHDMax Adaptive Time Stepping Courant HD
CrossSectionChecksRelativeToMaximumValues If CrossSectionChecksRelativeToMaximumValues is true, then changes to cross section values are relative to maximum values. If it is false, then changes are relative to durrent values
CrossSectionMaxRelativeVariation If PerformCrossSectionChecks is true, then cross section values cannot vary more than CrossSectionChecksMaximumRelativeVariation times either max values or current values (depending on the value of CrossSectionChecksRelativeToMaximumValues)
CrossSectionRelativeDepthLimit Cross sections are only checked if the relative water depth is above this limit.
DepthMaxRelativeChange When PerformDepthRelativeCheck, then the change in relative depth change must be less than RelativeDepthLimit. For small relative depths (below this limit), the limit value used is decreased down to a minimum of 0.02 when the relative depth is zero.

This is ony evaluated in closed part of the network.

Default value is 0.1. This cannot be below 0.02.

DischargeMaxChange Largest acceptable discharge change |dQ|. Also called "dDelQVal".
DischargeMaxRelativeChange Largest acceptable relative discharge change |dQ/Q|. Also called "dDelQ_QVal".
DischargeMaxRelativeChangeLimit Limit value for when relative discharge check is enabled, for |Q| less than this limit, the check is skipped. Also called "dDelQ_QLim".
DtFixed Adaptive Time Stepping fixed dt. Also used for Tabulated time stepping.

For adaptive time stepping this defines a fixed overall timestep that the adaptive time stepping procedure should hit exactly. It can e.g. be used to assure if results are printed exactly every hour, that the model hits that hour exactly.

It must be larger than DtMax.

If not applicable, set to Zero, which is the default.

DtMax Adaptive Time Stepping Maximum dt
DtMin Adaptive Time Stepping Minimum dt
FileFlushInterval Time between file flushes. Set to Zero to disable file flushes.

Default value is 10 seconds.

.
InitialTimeStep Initial time step in seconds. If TimeSteppingType is fixed, this is the timestep used during the entire simulation. Unit: [sec]
ItemNo Tabulated time step Item Number
PerformBoundaryCheck If true, then check boundaries during Adaptive Time Stepping
PerformCourantADCheck Adaptive Time Stepping Courant AD
PerformCourantHDCheck Adaptive Time Stepping Courant HD
PerformCrossSectionChecks If true, then perform checks on cross section flow area, water level, and surface area (MIKE URBAN method)
PerformDepthRelativeCheck If true, then relative water depth is checked in h-grid points (MIKE URBAN method)

Only performed for closed cross sections.

PerformDischargeCheck Enable checking of discharge change |dQ|
PerformDischargeRelativeCheck Enable checking of relative discharge changes |dQ/Q|.
PerformRunoffCheck If true, then check runoff inflow during Adaptive Time Stepping. It is using the same limits as the PerformBoundaryCheck.
PerformStructureCheck If true, then let structures calculate their preferred time step size
PerformWaterLevelCheck Enable checking of water level changes |dh|
PerformWaterLevelRelativeCheck Enable checking of relative water level changes |dh/depth|
PumpAccDecVarDtRel When a pump is accelerating or decelerating, this factor defines the maximum time step accepted by the pump.

A value of zero specifies that the DtMin time step will be used, and a value of one specifies that the DtMax time step is acceptable.

Default value is zero, meaning that when pumps are accelerating or decelerating, the simulation will run with DtMin.

TabulatedTSFile Tabulated time step Filename
TabulatedTSFilename Tabulated time step Filename
Obsolete
TimeStepIncreaseMax Maximum factor with which the time step can be increased. A value of 1.3 means that the timestep can only increase with 30%. Decrease of time step is not limited. Defaults to 2.
Type Type of time stepping taking place
WaterLevelMaxChange Largest acceptable water level change |dh| Also called "dDelhVal"
WaterLevelMaxRelativeChange Largest acceptable relative water level change |dh/depth| Also called "dDelh_hVal"
WaterLevelMaxRelativeChangeLimit Limit value for when relative water level check is enabled, for depth less than this limit, the check is skipped. Also called "dDelh_hLim"

Methods

EqualsDetermines whether the specified object is equal to the current object.
(Inherited from Object)
FinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object)
GetHashCodeServes as the default hash function.
(Inherited from Object)
GetTypeGets the Type of the current instance.
(Inherited from Object)
MemberwiseCloneCreates a shallow copy of the current Object.
(Inherited from Object)
ToStringReturns a string that represents the current object.
(Inherited from Object)

See Also