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Welcome to the next generation MIKE+ Documentation

The Main MIKE+ Modules

Model Manager

The Model Manager is the main module of MIKE+ and includes a common data module for all types of applications. Input editors for all simulation engines are included irrespective of the installed simulation engines.

Collection Systems

The main module for Collection Systems is CS-Pipeflow, which includes DHI’s MIKE 1D engine. With MIKE+ CS-Pipeflow you get access to:

  • Hydrodynamic simulation of networks
  • Long term statistics

Hydrodynamic Simulation

The MIKE 1D Hydrodynamic Pipe Flow Model solves the complete St. Venant (dynamic flow) equations throughout the drainage network (looped and dendritic), which allows for modelling of backwater effects, flow reversal, surcharging in manholes, free-surface and pressure flow, tidal outfalls and storage basins. The MIKE 1D hydrodynamic engine has been designed to handle any type of pipe network system with alternating free surface and pressurized flows as well as open channel network and pipes of any shape. Virtually any construction can be described including pumps, weirs, orifices, inverted siphons, etc.

The computational scheme uses an implicit, finite-difference numerical solution of the St. Venant flow equations. The numerical algorithm uses a self-adapting time-step, which provides efficient and accurate solutions in multiple connected branched and looped pipe networks. This computational scheme is applicable to unsteady flow conditions that occur in pipes ranging from small-profile collectors for detailed urban drainage, to low-lying, often pressurized, sewer mains affected by varying outlet water levels. Both sub-critical and supercritical flows are treated by means of the same computational scheme that adapts to the local flow conditions. In addition, flow phenomena, such as backwater effects and surcharges, are precisely simulated.

Long Term Statistics

MIKE 1D Long Term Statistics (LTS) allows that a collection system network with intermittent hydrological inputs can be setup for a long-term simulation, covering a continuous historical period, possibly over several years. The system automatically combines dynamic pipe flow simulations during wet weather and simple hydrological simulation during dry weather periods, which results in accurate computation of wastewater treatment plant loads, CSOs and other system outputs, while preserving rationality in use of computational resources. The results are presented both in the form of time series and a range of statistical parameters for selected variables. By running simulations with the current system configuration and the planned upgrade, impacts of the planned investments (e.g. new sewers, retention tanks, RTC schemes) on the system performance can be tested. This allows the user to develop the optimal rehabilitation / upgrade strategy, e.g. for achieving the consent with the environmental regulators' requirements.

Rivers

The main module for river networks is CS-Rivers, which includes DHI's MIKE 1D engine for hydrodynamic modelling.

MIKE 1D's hydrodynamic module solves the complete St. Venant (dynamic flow) equations throughout the river network (looped and dendritic), which allows for modelling of backwater effects, flow reversal, surcharging in closed sections, free-surface flows, tidal outlets and storage in reservoirs.

The computational scheme uses an implicit, finite-difference numerical solution of the St. Venant flow equations. The numerical algorithm may use a self-adapting time-step, which provides efficient and accurate solutions. Both sub-critical and supercritical flows are treated by means of the same computational scheme that adapts to the local flow conditions. In addition, flow phenomena, such as backwater effects and surcharges, are precisely simulated.

2D overland

MIKE+ 2D overland module uses DHI's 2D engine MIKE 21 FM. This engine solves the two-dimensional St. Venant (dynamic flow) equations, using a cell-centered finite volume method. The time integration is performed using an explicit scheme and the numerical solution uses a self-adapting time step for optimizing stability and simulation times. The spatial discretisation can either be done through a rectangular grid or a flexible mesh.

The 2D overland module can be used to simulate free-surface flows to describe detailed flows in channels or describe surface floods from e.g. surcharging collection system networks, rivers, or sea surges.

Cross-domain modules

The following modules may be used in combination with the Collection Systems, Rivers, and/or 2D overland modules.

CS-Rainfall-Runoff

MIKE+ CS-Rainfall-Runoff modules may be used with both the Collection Systems and Rivers modules. It includes the MIKE 1D engine for rainfall-runoff modelling. With MIKE+ CS-Rainfall-Runoff you get access to:

  • Several types of surface runoff models
  • Rainfall dependent infiltration (RDI)

Surface Runoff

MIKE 1D Surface Runoff includes several types of surface runoff computation for the description of the urban catchment surfaces. This means that the surface runoff computations can be adjusted according to the amount of available information. The models run with well proven default hydrological parameters, which can be adjusted for better accuracy. The computed hydrographs are used as input to the MIKE 1D Pipe Flow model.

Rainfall Dependent Infiltration

MIKE 1D Rainfall Dependent Infiltration provides detailed, continuous modelling of the complete land phase of the hydrological cycle, providing support for urban, rural and mixed catchments analyses. Precipitation is routed through four different types of storage: snow, surface, root zone and ground water, resulting in more accurate hydrographs. Instead of performing hydrological load analysis of the sewer system only for short periods of high intensity rainstorms, a continuous, long-term analysis can be used to look at periods of both wet and dry weather, as well as inflows and infiltration to the sewer network. This provides a more accurate picture of actual loads on treatment plants and combined sewer overflows.

CS-Control

MIKE+ CS-Control module can be used in combination with the Collection Systems module. It allows real-time control devices to be included in defining the urban drainage sewer network model. A selection of controllable devices is provided, along with a fully generic specification of control rules for any simple or complex global control scheme. The system allows the application of setting or set point (PID controller) based control functions, selected on the basis of logical evaluation of the actual system states (reactive control) or after the specified time series.

Transport

Under the name Transport, the MIKE 1D engine provides several modules for the simulation of sediment transport and water quality for both catchments surfaces and networks. Since pollutants are carried by sediment, sediment transport processes and water quality in sewer systems are closely interconnected. This is important for understanding phenomena like the first flush effect, which can only be simulated with a description of the temporal and spatial distribution of sediment deposits on the catchment surface and in the sewer system.

MIKE 1D can model these complex mechanisms using its Surface Water Quality (SWQ), Advection-Dispersion (AD), Water Quality (MIKE ECO Lab) and Sediment Transport (ST) modules.

In MIKE+ Transport the following can be modelled:

  • Stormwater Runoff Quality (SWQ)
  • Catchment Discharge Water Quality
  • Advection-Dispersion (AD)
  • Water Quality (MIKE ECO Lab)
  • Sediment Transport (ST)

Stormwater Runoff Quality

The Storm-water Runoff Quality (SWQ) is for use with the Rainfall-Runoff module only. The primary role of the Storm-water Runoff Quality (SWQ) module is to provide a physically-based description of the relevant processes associated with sediments and pollutants due to surface runoff, and then provide surface runoff sediment and pollutant data for the other pipe sewer network sediment transport and water quality modules. The following processes can be accounted for:

  • Build-up and wash-off of sediment particles on the catchment
  • Surface transport of pollutants attached to the sediment particles
  • Build-up and washout of dissolved pollutants in potholes and stilling basins

Sediment deposits can greatly reduce the hydraulic capacity of sewer pipes by restricting their flow area and increasing the bed friction resistance. The Pipe Sediment Transport functionality included in Pollution Transport can account for these problems, by simulating pipe sewer network sediment transport-including deposition and erosion from non-uniform (graded) sediments. Contributions from rainstorm wash-off and dry-weather wastewater flow can be included. The Sediment Transport feature runs in conjunction with the dynamic flow routing, thereby simulating dynamic deposition of sediment and providing feedback due to the change in pipe area and resistance caused by sediment deposition. The following issues can be addressed:

  • Prediction of sediment deposit locations and associated pollutants and metals in the sewer system
  • Prediction of reduction in hydraulic capacity due to observed and simulated sediment deposits
  • Analysis of the sewer system due to modified regulation strategies

Advection-Dispersion (AD)

The Advection-Dispersion (AD) module may be used with all modules: Collection Systems, Rivers, and 2D overland. It simulates the transport of dissolved substances and suspended fine sediments in pipe and river networks as well as on the surface. Conservative materials as well as those that are subject to a linear decay can be simulated. The computed discharges, water levels, and cross-sectional flow areas are used in the AD module computation. The solution of the advection-dispersion equation is obtained using an implicit, finite-difference scheme which has negligible numerical dispersion. Concentration profiles with very steep fronts can be accurately modelled. The computed results can be displayed as longitudinal concentration profiles and pollutant graphs, which could be used at the inflow to a sewage treatment plant or an overflow structure.

The AD module can be linked to the Long Term Statistics module to provide long-term simulations of pollutant transport.

Water Quality (MIKE ECO Lab)

Water Quality module with MIKE ECO Lab can be used with the Collection Systems module, the Rivers module and/or the 2D overland module. Different biological processes can be modelled by means of MIKE ECO Lab working in conjunction with the Advection-Dispersion part of MIKE+ Water Quality. It provides many options for describing the reaction processes of multi-compound systems, including degradation of organic matter, bacterial fate, exchange of oxygen with the atmosphere and oxygen demand from eroded sewer sediments. This allows realistic analysis of complex phenomena related to water quality in sewer systems.

The module includes diurnal variation of foul flow discharges and user-specified concentrations of foul flow components. The sediment types are foul flow organic sediments, and fine and course mineral in-pipe sediments originating from catchment runoff, potholes and stilling basins. The following can be accounted for with this module:

  • Decay of BOD/COD in bio-film and water phase
  • Hydrolysis of suspended matter
  • Growth of suspended biomass
  • Oxygen consumption from decay of BOD/COD, bio-film and erosion of sediment
  • Re-aeration
  • Bacterial fate
  • Interaction with sediments for nutrients and metals

Sediment Transport

This module is used for sediment transport modelling in pipes and river networks. It comes in a basic version tailored primarily for application to pipe networks, and an advanced version giving full access to all its modelling capabilities suited for e.g. long term assessment of river morphology changes. It can include various model types (e.g. van Rijn, Meyer-Peter & Muller, Engelund-Hansen, Engelund-Fredsoe, Yang, or user-defined empirical formulas). Graded or mixed sediment descriptions can be applied by defining a number of different sediment fractions, which are treated separately by the sediment transport module. Sediment transport is computed from hydrodynamic conditions, and dynamic changes in the river morphology can in return affect the hydrodynamic conditions.

SWMM collection systems

MIKE+ includes the SWMM (EPA's Storm Water Management Model) engine for storm water modelling. SWMM allows for the hydrodynamic simulation of flows and water levels in urban storm drainage and wastewater collection networks, thus providing an accurate information about the network functionality under a variety of boundary conditions. The model can be enhanced by the variety of real-time control functions. The simulations can be carried out for single events.

Water Distribution

MIKE+ for Water Distribution comes with the following modules:

  • WD-Basic: For modelling water distribution networks using EPANET engine
  • WD-Tools: Allows for modelling advanced features including fire flow, network vulnerability, cost analysis, shutdown planning, flushing, pressure dependent demands, variable speed pumps, real-time control and optimization.

WD-Basic

Allows standard modelling of water distributing networks using the EPANET engine including water age/quality.

WD-Tools

With MIKE+ Water Distribution Tools you get the following capabilities:

Fire Flow Analysis

Calculating water availability for fire protection requirements is one of the most frequent modelling tasks of water utility. The Fire Flow Analysis module allows you to calculate the available flow for the design pressure or to calculate the residual pressure for the design flow.

There are two basic ways to model a fire flow:

  • Specify a design fire flow rate and compute the available fire flow pressure
  • Specify a design fire flow pressure and compute the available fire flow rate

Network vulnerability

Network vulnerability is used to predict the water distribution system response to pipe break situations, planned reconstructions, and other scenarios of limited water supply. Network vulnerability also allows the development of a pipe ranking based on the importance for the water supply, such importance can be then considered into a pipe rehabilitation and construction plan.

Cost Analysis

Cost analysis allows you to review the energy consumption results on more details, create tabular outputs, and great graphs of pump utilization, average power consumption, and costs.

Shutdown Planning

The Shutdown Planning analysis allows to determine the impact of pipe maintenance work on the water supply conditions. It helps the user to define the shutdown, find isolation valves, run hydraulic simulations and evaluate simulation results.

Management of shutdowns contains the following tools:

  • Planning shutdown
  • Close pipes for selection isolation valves
  • Analyse shutdown
  • Compare results before and during the shutdown

Flushing Analysis

Flushing of pipelines is a practice done since the early days of municipal water systems. The conventional way to flush pipelines was to simply open selected fire hydrants letting them flow until the running water showed a clean appearance. This is still an effective strategy in many cases. However, these days many water utilities do unidirectional flushing (UDF), which is a more engineered and effective way to flush pipelines. UDF involves closing or opening selected valves to direct flow through target pipes in order to achieve higher velocities for the same hydrant flows. The set of valves that need to be operated and hydrant that is opened is called a flushing sequence. A UDF design consists of a series of flushing sequences that are run in a particular order so that water is always being drawn from clean parts of the system.

Extended Rule-Based Controls

Rule-Based Controls allow link status and settings to be based on a combination of conditions that might exist in the network over an extended period simulation. In order to allow for modelling of chains of pumps or valves chains in efficient way, the EPANET Rule-based control syntax was extended by adding LIKE keyword, for example.

Optimization

This functionality supports scheduling of pumps and operation of control valves. The optimization is based on optimization algorithms that can run with any extended period analysis model.

Online analysis

This functionality enables mapping real-time data available online to the model elements described in the WD model network. This functionality is for use with WD Online.

Multi-species analysis

The multi-species analysis allows modelling water quality for any system of multiple, interacting chemical species. This module is based on the EPANET MSX engine.

Autocalibration

This functionality is based on optimization algorithms, and is meant to calibrate a network model against a number of provided measured time series of pressure, flow, head or water depth. It can be used for optimizing the friction in selections of pipes, the water demands, leakage and/or the Open/Closed status of pipes and valves.