PREPRINT: Comparison of deep learning and hand crafted features for mining simulation data

TL;DR

This paper compares deep learning and hand-crafted features for automated analysis of complex CFD simulation data, demonstrating both approaches' effectiveness in predicting aerodynamic forces.

Contribution

It introduces a large CFD dataset and evaluates deep learning versus hand-crafted features for extracting meaningful insights from high-dimensional flow data.

Findings

Deep learning methods perform well in predicting aerodynamic forces.

Hand-crafted features also effectively describe CFD data.

Both approaches are suitable for automated CFD data analysis.

Abstract

Computational Fluid Dynamics (CFD) simulations are a very important tool for many industrial applications, such as aerodynamic optimization of engineering designs like cars shapes, airplanes parts etc. The output of such simulations, in particular the calculated flow fields, are usually very complex and hard to interpret for realistic three-dimensional real-world applications, especially if time-dependent simulations are investigated. Automated data analysis methods are warranted but a non-trivial obstacle is given by the very large dimensionality of the data. A flow field typically consists of six measurement values for each point of the computational grid in 3D space and time (velocity vector values, turbulent kinetic energy, pressure and viscosity). In this paper we address the task of extracting meaningful results in an automated manner from such high dimensional data sets. We propose deep learning methods which are capable of processing such data and which can be trained to solve relevant tasks on simulation data, i.e. predicting drag and lift forces applied on an airfoil. We also propose an adaptation of the classical hand crafted features known from computer vision to address the same problem and compare a large variety of descriptors and detectors. Finally, we compile a large dataset of 2D simulations of the flow field around airfoils which contains 16000 flow fields with which we tested and compared approaches. Our results show that the deep learning-based methods, as well as hand crafted feature based approaches, are well-capable to accurately describe the content of the CFD simulation output on the proposed dataset.