Research Interests

Environmental hydraulics, sediment transport, multiphase flow, CFD, scientific machine learning applications in hydrodynamics modeling


The major thrust in our research is to develop and utilize novel computational models, both physics-based and data-driven, for problems in environmental hydraulics and water resource engineering in general. Complementary to computational modeling, we also do some lab experiments and analytical work.

Numerical Models and Tools

  • Hydrograd.jl: Computational Hydrodynamics with Automatic Differentiation for Scientific Machine Learning. A Julia package for universal shallow water equations.
  • OpenFOAM: Our major research package with multiple applications
  • pyHMT2D: Python package for 2D Hydraulic Modeling Tools
  • dl4HM: Deep-learning for Hydraulics Modeling, a python package for building data-driven machine learning models.

Experimental Work

  • Image-based flow measurement and improvement with machine learning
  • Scour around porous hydraulic structures
  • Rock weir hydraulics
  • Sediment movement through synthetic turf

External Research Grants/Awards/Coorperative Agreements

  • Harnessing Physics-Informed Machine Learning to Improve Image-Based Streamflow Measurements, PI, USGS, 2023-2026
  • Two-dimensional computational hydraulics modeling and automation, PI, FHWA (through Genex), 2024-2025
  • Local scour around bridge piers, PI, FHWA (through Genex), 2024-2025
  • PFI-RP: Novel coated geotextile to enhance water drainage from soil, PI at Penn State (Lead PI: Dr. Jie Han at University of Kansas), NSF, 2023-2026
  • Mentoring Institute for Sediment Transport (MIST) for Early Career Professionals at the EWRI World Environmental and Water Resources Congress and the AGU Fall Meeting, PI at Penn State (Lead PI: Dr. Jennifer Duan at University of Arizona), NSF, 2023-2024
  • In-situ stiffening and upgrading of ballasted rail track beds via cement grout injection, co-PI (PI: Dr. Farshad Rajabipour), Center for Integrated Asset Management for Multi-modal Transportation Infrastructure Systems (CIAMTIS), U.S. DOT Region 3 University Transportation Center, 2021-2022 (no cost extension to 2023)
  • Guidelines for selection and application of Manning's roughness values in two-dimensional hydraulics models, PI, NCHRP, 2020-2023
  • Evaluation of dust suppressants used on gravel roads – Water quality impacts and dust suppression efficacy, co-PI (PI: Bill Burgos), PA Department of Environmental Protection, 2020-2021
  • Nature-based solutions for river restoration, PI, NSF, 2019-2022.
  • Respiration in hyporheic zones: connecting mechanics, microbial biogeochemistry, and models, PI, DoE (sub-award through UT Austin), 2017-2020 (no-cost extension to 2021)
  • Nature-like Fish passage design for the York Haven Hydroelectric Dam, PI, (co-PIs: Johnson, P. A. and Ferreri, C. P.), Cube Hydro Partners, 2017-2020 (no-cost extension to 2021)
  • Impact of Oil & Gas Wastewater Disposal on Lake and River Sediments, co-PI (PI: Burgos, W. D., other co-PIs: Warner, N. R., Drohan, P. J., Vanden Heuvel, J. P. , and Dorman, F. L., NSF. 2017-2020 (no-cost extension to 2021)
  • Evaluation of erodibility of sand infill placed in synthetic grass, Phase 3, co-PI (25%; PI: M. Xiao),  Watershed Geosynthetics LLC, 2020
  • Evaluation of erodibility of sand infill placed in synthetic grass, Phase 2, co-PI (30%; PI: M. Xiao), Watershed Geosynthetics LLC, 2020
  • Evaluation of erodibility of sand infill placed in synthetic grass, Phase 1, co-PI (30%; PI: M. Xiao), Watershed Geosynthetics LLC, 2019-2020
  • GRS-IBS specification modification, co-PI (PI: Xiao, M.), PennDOT, 2019-2020
  • Robust ecohydraulic 3D modeling tools for rivers with complex instream structures, PI, U.S. Bureau of Relcamation, 2017-2020
  • Three-dimensional computational modeling of turbulent flow field, bed morphodynamics and liquefaction adjacent to munitions", PI, Strategic Environmental Research and Development Program (SERDP), 2017-2020. (no-cost extension to 2021)
  • Collaborative Research: Visualization, analysis, and HPC modeling of subglacial hydrology from high-resolution 3D conduit scans acquired with a novel sensor, PI, NSF, 2015-2017 (no-cost extension to 2018)
  • Assignment agreement of Intergovernmental Personnel Act (IPA): modeling of scour and soil erodability test apparatus, PI, U.S. Army Corps of Engineers, 2015
  • Accuracy evaluation and verification of FISP sediment samplers through CFD modeling, PI, USGS, 2015-2016
  • Quantitative modeling tools for scour and morphological impact due to large wood debris structures, PI, U.S. Bureau of Relcamation, 2014-2017
  • Pore-scale modeling of turbulent flows with realistic and physically correct particle arrangement, PI, U.S. Army Corps of Engineers, 2013-2015
  • CNIC: U.S.-Danish Research Planning Visit to Catalyze Computational and Experimental Research on Scour Protection of Offshore Wind Farms, PI, National Science Foundation, 2012-2013
  • Assessment of the effects of regional channel stability and sediment transport on roadway hydraulic structures, PI, Texas DOT, 2011-2013
  • Empirical flow parameters-A tool for hydraulic model validity assessment, co-PI, (PI: Theodore Cleveland, Texas Tech University), Texas DOT, 2010-2012
  • Synthesis of Hydrologic and Hydraulic Impacts, co-PI (PI: Hatim Sharif, University of Texas at San Antonio), Texas DOT, 2010-2011
  • Two-dimensional modeling of hydrodynamics, sediment transport, bed scour and armoring in St. Clair River, G. Parker (PI), X. Liu (Co-PI), sponsored by International Joint Commission, International Upper Great Lakes Study, 2008

Internal Research Grants

  • Solving Surface Shallow Water Equations using Machine Learning Algorithms, Penn State ICDS Seed Grant, 2020
  • 3D data acquisition and 3D printing to construct “Digital Twins” for water and biogeochemical research, PSIEE, Penn State University, 2015