Hou is known for his research on multiscale analysis and singularity formation of the three-dimensional incompressible
Euler and
Navier–Stokes equations. He is an author of the monograph
Multiscale finite element methods. The multiscale finite element method developed by Hou and his former postdoc, Xiao-Hui Wu, was one of the earliest multiscale methods and has found many applications from the engineering community. A variant of his method has been adopted by several major oil companies in their new generation of flow simulators. Hou has worked extensively on computational and analytical aspects of the Euler and Navier-Stokes equations. In 2014, Hou and his former postdoc, Guo Luo, presented convincing numerical evidence that the axisymmetric Euler equations develop finite time singularity from smooth initial data. In 2022, Hou and his former PhD student Jiajie Chen proved the finite time singularity of the axisymmetric Euler equations with smooth data and boundary (the so-called Hou-Luo blowup scenario). Hou’s recent work on the potentially singular behavior of the three-dimensional Navier-Stokes equations has also generated a lot of interests. His early work on the convergence of the point vortex method for incompressible Euler equations was unexpected and considered a breakthrough. The level set method developed by Hou and co-workers was the first level set method for multiphase flows and has found many applications. The Small-Scale Decomposition method developed by Hou-Lowengrub-Shelley was considered a tour de force for fluid interface problems and has been used widely in computational fluid dynamics, materials science, and biology. Hou was founder of "SIAM Journal on Multiscale Modeling and Simulation", and he served as the editor-in-chief from 2002 to 2007. He was also cofounder of
Advances in Adaptive Data Analysis. ==Awards and honors==