The defining feature of modern MIKE 21 is its . Older versions were purely structured. The FM allows:

Historically, numerical modeling systems relied on structured, rectilinear grids. While simple to compute, rectangular grids struggle with intricate, curved geometries like meandering river banks or complex port breakwaters.

| | Specific Module | Primary Function & Application | | :--- | :--- | :--- | | Hydrodynamics | Hydrodynamic (HD) Module | Simulates water level changes and flows (currents) driven by tides, winds, waves, river inflows, and atmospheric pressure. The foundation for all other modules. | | Hydraulics | Advection-Dispersion (AD) Module | Models the transport, mixing, and degradation of dissolved substances like salinity, temperature, and coliform bacteria. | | Hydraulics | MIKE ECO Lab / Oil Spill | An advanced ecological modelling tool that describes complex biological and chemical processes. It can simulate everything from eutrophication and algal blooms to the fate of oil spills. | | Hydraulics | Inland Flooding | A dedicated option within the HD module for simulating two-dimensional overland flow, crucial for inland flooding and urban drainage studies. | | Sediment Transport | Mud Transport (MT) Module | Models the erosion, transport, and deposition of cohesive sediments like silt, mud, and clay under currents and waves. | | Sediment Transport | Sand Transport (ST) Module | Calculates the transport of non-cohesive sand, often used to study shoreline evolution and the impact of engineering works on beaches. Uses multiple transport formulas. | | Waves | Spectral Waves (SW) Module | A third-generation spectral wind-wave model that simulates the growth, propagation, and decay of wind-generated waves and swells in large offshore and coastal areas. | | Waves | Boussinesq Waves (BW) Module | A more detailed model for simulating wave propagation and transformation in harbours and near coastal structures. It explicitly models wave breaking, run-up, and non-linear interactions. | | Other Tools | Particle Tracking (PT) | Simulates the trajectory of dissolved or suspended particles for risk analysis, spill response, and studying larval dispersal. | | Other Tools | Morphological Analysis (MA) | Simulates long-term shoreline evolution by integrating the results of hydrodynamic, wave, and sediment transport modules. | | Other Tools | Mooring Analysis | Models the dynamic behaviour of moored vessels under the influence of wind, waves, and currents, also calculating forces on fenders and mooring lines. |

At the center of this ecosystem is , the industry-standard software suite for two-dimensional (2D) free-surface flow modeling. Developed by the Danish Hydraulic Institute (DHI) , MIKE 21 simulates water levels, waves, currents, and sediment dynamics across oceans, coastal waters, estuaries, and floodplains. The Core of MIKE 21: Flexible Mesh (FM) Architecture

This comprehensive guide explores the core capabilities, essential modules, and real-world applications of MIKE 21. Core Architecture: Flexible Mesh vs. Rectangular Grid

Divided into cohesive (mud) and non-cohesive (sand) transport modules, this tool predicts morphological changes over time.

Beyond the core flow engine, MIKE 21 includes a suite of specialized modules for advanced analysis:

Water resource management, coastal engineering, and environmental protection are becoming increasingly complex in the face of climate change and rapid urbanisation. For decades, engineers and scientists have relied on advanced numerical modelling tools to understand and predict the behaviour of our aquatic environments. Among these, , developed by the globally renowned Danish Hydraulic Institute (DHI) , stands out as a true powerhouse. But what exactly is MIKE 21, and why is it the go-to solution for professionals in over 140 countries?

MIKE 21 is highly modular, meaning users can purchase or utilize only the components necessary for their specific project. Key modules include: 1. MIKE 21 Hydrodynamic (HD) Module