Back

Print

Microscale models

Microscale models of the atmosphere are designed to simulate small-scale flow systems (e.g. turbulence, vortices, air flows over obstacles) with a horizontal length scale ranging between a few meters and some 100 m.

Different microscale models are operated at the Institute of Atmospheric Physics, each one optimized for a specific purpose. They differ by the physical approximation (anelastic vs. compressible) or by the type of the numerical method. Microscale models are used, for example, for large-eddy simulations (LES) of turbulence, to calculate the behaviour of wake vortices and condensation trails behind aircraft and to simulate the flow over small obstacles such as hills, trees, buildings or noise barriers.

For wake vortex applications a number of models and model systems have been developed in parts together with other DLR institutes.

• Large eddy simulations of the wake vortex behaviour in different meteorological environments are conducted with the code MGLET. MGLET has been extended by a hybrid methodology that allows to „fly“ a hifi solution of the flow around an aircraft (from TAU-Code) through the simulation domain. This way the whole life cycle from early vortex rollup to final decay can be accessed.
   
• The wake vortex model P2P provides fast predictions of wake vortex transport and decay together with uncertainty allowances of defined probability.
   
• The Airborne Meteo Data Fusion Algorithm (am+fusion) combines meteorological measurements of several aircraft employing a Kalman filter for airborne wake vortex prediction with P2Pa in WEAA (see below).
   
• The Wake Encounter Advisory and Avoidance System (WEAA) is an airborne system for the identification and avoidance of imminent encounters of wake vortices shed by neighbouring aircraft.
   
• The Wirbelschleppen Vorhersage- und Beobachtungssystem (WSVBS) predicts weather-dependent dynamic aircraft separations for approaches to closely-spaced parallel runways and single runways.
   
• The Wake Vortex Scenarios Simulation Package (WakeScene) accomplishes Monte Carlo simulations of arrivals and departures and estimates the respective frequency and severity of wake vortex encounters. WakeScene supports sensitivity analysis, optimization, and safety cases for new aircraft types, wake vortex procedures and systems.