TASS Driven Algorithms for Wake Prediction

Three-Phased Wake Vortex Decay

“…His concept is based upon theoretical arguments with guidance from direct numerical simulations of the incompressible Navier-Stokes equations. A two-phased level of decay has also been described by Holzapfel et al 5,6 and Proctor et al, 7,8 with the initial decay (phase 1) being weak, followed by a rapid decay (phase 2) associated with the onset of vortex linking. These studies were based on large eddy simulations (LES), and showed that the rate of vortex decay (and lifetime) is a function of stratification as well as ambient turbulence.…”

“…8 Recent improvements in the post-processing analysis software, now allow better detection of circulation during the ring phase, and reveal a third phase as shown in Figure 5a and 5b.…”

“…They are the Deterministic 2-Phased (D2P) model 6 and the TASS Driven Algorithm for Wake Prediction (TDAWP). 8,9 Both D2P and TDAWP account for two-phased vortex decay. Other studies rooted in laboratory experiments, field data, and theory, have assumed a single-phased decay function for their predictions.…”

Evaluation of Fast-Time Wake Vortex Prediction Models

“…Candidate models include the AVOSS Prediction Algorithm (APA) 15,22 with the OGE transport and decay computed using either Sarpkaya 23 , the TASS Driven Algorithm for Wake Prediction (TDAWP) 24 , or the Deterministic 2-Phase (D2P) 25 model (as re-coded from literature).…”

“…The TDAWP model has separate prognostic equations for vortex descent rate and 5-15 m average circulation, and it applies these separately to both the port and starboard vortices 24 . The formulation is driven by parametric studies from LES using TASS 30,31 .…”