1. Introduction

2. Background  
2.1. Overview of DR techniques  
2.2. Manifold alignment  
2.4. Intermediate surrogate modeling approaches  

3. Multi-fidelity surrogates for the prediction of high-dimensional field outputs  
3.1. Corrective approaches  
3.2. Mapping approaches  
3.3. Fusion approaches  
3.4. General remarks on the different approaches  

4. Description of the test cases  
4.1. Viscous free fall of a ball  
4.3. Two-dimensional pressure coefficient field around an airfoil  

5. Benchmark methodology  
5.1. Training and validation data  
5.2. Comparison metrics  

6. Results and discussions  
6.1. Viscous free fall of a ball without ground  
6.2. Viscous free fall of a ball with ground  
6.3. Pressure coefficient field around a NACA 0015 airfoil  
6.6. Computational training cost  
6.7. Discussions  

7. Concluding recommendations