Transonic Modelling in Formation Flight

Aircraft flying in formation flight maintain fuel cost savings. The quantification of the induced drag savings, roll trim authority and the effect of compressibility on these are of prime importance. The CFD simulation of this problem entails splitting the problem into 3 parts: lead aircraft, vortex propagation and trailing aircraft. Compressible CFD technology has recently been used to model the problem and have estimated induced drag savings to be about 35%. However these simulations have used approximate models that have been tuned using empirical and 2D CFD simulations. Furthermore, the work has modelled the 3 sub-problems separately as 3 individual problems. Improvements on this work include removing the approximate models and replacing it with a 3D CFD simulation.

 

 

Towards a hybrid CFD platform for investigating aircraft trailing vortex interactions

The aim of Donovan Changfoot's project is to develop a hybrid finite-volume-high-order-finite-difference solver capable of investigating aircraft trailing vortices. This is achieved by coupling Elemental, the finite volume code, and Essense, the 6th order finite difference code, using Summation-By-Parts and Simultaneous-Approximation-Terms. In the interest of industrial relevance, the resultant platform will then be used to investigate the trailing vortex interaction behind the NASA Common-Research-Model up to 20 wingspans downstream.