University of Iowa
University of Iowa
National Taiwan University
It is a great fortune working with students and colleagues from all over the world, on learning, discovery, and applications.
Subjects at the interface of physics and engineering
Dr. Shen's research areas are in granular mechanics and sea ice dynamics. Below are several project areas.
Wave Propagation under Ice Covers
Arctic ice reduction is the most well-known consequence of climate change. Increased open water area enhances wind fetch thus amplifies the wave intensity. The escalation of waves in the Arctic has unforeseen effects on the formation and decay processes of sea ice, ocean mixing and stratification, coastal erosion, and possibly the Arctic ecosystem. All existing wave forecast models need to be improved to account for a dynamically changing ice covers. This study provides a rheological model for a broad range of ice covers. This model contains two parameters, viscosity and elasticity, both are related to the ice cover morphology. With these two parameters the attenuation and wave speed in different ice covers are determined. Current analysis focuses on the relation between the morphology and the viscoelastic properties of an ice cover, and the effect of various rheological models on the wave responses.
Pancake Ice Formation
Pancake ice is the first form of sea ice formation over open water in the polar and sub-polar oceans. Their formation is associated with waves. The size, thickness and the internal structure of the pancake ice affect heat and momentum transfer between air and ocean, and the marine biology that lives off the sea ice. This study utilizes theoretical analysis, computer simulation, and field observations in the Arctic and Antarctic, as well as laboratory experiments to determine the relation between the pancake ice floe size and the wave field, and the equilibrium ice cover thickness due to wave rafting.
Transitional Granular Flows
Granular materials can behave like a solid as in a sand pile, a liquid as in a landslide, or a gas as in a dust storm. Many industrial applications require processing granular materials that can only be design by trial-and-error. This is because unlike a regular fluid, granular materials can "solidify, melt, and evaporate" abruptly. Many industries suffer equipment failure due to the lack of understanding of how granular materials transition from one regime to the other. Future human explorations to the moon and Mars require in-situ resource utilization. Thus a better understanding of granular materials is needed to enable precise control and engineering work involving these materials.
Constitutive relations for a dry particulate material, including the effect of particle spin, particle shape, as well as the distribution of particle size. Transition of quasi-static to rapidly sheared flows. Effects of electrostatic and other long range forces on granular assemblies. Interaction of machine boundaries with granular materials. Computational simulation of granular assemblies and polymer flows.
Sea Ice Dynamics
Constitutive relations of marginal ice zones. Wave attenuation due to ice floe interactions in a wave field. Ice drift and collision rate in wave fields. Formation of pancake ice, limiting size and thickness of pancake ice covers. Ice productions rate in a wave field. Full rheological properties and dispersion relation of a general ice cover. Remote sensing analysis of ice motion. Laboratory experiments of ice formation and evolution using cold room facilities. Field experience in the Arctic (Greenland Sea, Beaufort and Chukchi Seas) and the Antarctic (McMurdo/Scott Base).
- Fellow, Engineering Mechanics Institute, ASCE
- Kirstin Craig Memorial Faculty Award
- Outstanding Advisors, Clarkson University Phalanx Award
- Million Dollar Club of Clarkson University Research Accomplishment
- Albert D. Merrill Faculty Prize, Clarkson University
- William Evans Fellow, Otago University, New Zealand
- Walter L. Huber Civil Engineering Research Prize, ASCE
- ASCE/Engineering Foundation Research Institute Award
10 Most recent
- Cheng, S., Rogers, W. E., Thomson, J., Smith, M., Doble, M., Wadhams, P., Kohout, A. L., Lund, B., Persson, O., Collins, C. O., Ackley, S. F., Montiel, F. and Shen, H. H. (2017), Calibrating a Viscoelastic Sea Ice Model for Wave Propagation in the Arctic Fall Marginal Ice Zone. J. Geophys. Res. Oceans. doi:10.1002/2017JC013275.
- Shen, H.H. (2017) Wave ice interactions, Encyclopedia of Marine and Offshore Engineering, doi:10.1002/9781118476406.emoe086.
- Zhao, X., S. Cheng, and H.H. Shen (2017), Nature of wave modes in coupled viscoelastic layer over water, J. Eng. Mech., 143(10): 04017114, doi:10.1061/(ASCE)EM.1943-7889.0001332.
- Thomson, J., S. Ackley, H. H. Shen, and W. E. Rogers (2017), The balance of ice, waves, and winds in the Arctic autumn, Eos, 98, doi:10.1029/2017EO066029. Published on 23 January 2017.
- Thomson, J., Y. Fan, S. Stammerjohn, J. Stopa, W.E. Rogers, F. Girard-Ardhuin, F. Ardhuin, H. Shen, W. Perrie, H. Shen, S. Ackley, A. Babanin, Q. Liu, P. Guest, T. Maksym, P. Wadhams, C. Fairall, O. Persson, M. Doble, H. Graber, B. Lund, V. Squire, J. Gemmrich, S. Lehner, B. Holt, M. Meylan, J. Brozena, and J.-R. Bidlot (2016) Emerging trends in the sea state of the Beaufort and Chukchi seas, Ocean Modelling, 10.1016/j.ocemod.2016.02.009.
- Rogers, W. E., Thomson, J., Shen, H. H., Doble, M. J., Wadhams, P, and Cheng, S. (2016) Dissipation of wind waves by pancake and frazil ice in the autumn Beaufort Sea, J. Geophys. Res. – Oceans, DOI 10.1002/2016JC012251.
- Zhao, X. and Shen, H. H. (2016) A diffusion approximation for ocean wave scatterings by randomly distributed ice floes, Ocean Modelling, http://dx.doi.org/10.1016/j.ocemod.2016.09.014.
- Sree, D.K.K. Law, A. W.-K., and Shen, H.H. (2016) An experimental study on the interactions between surface waves and floating viscoelastic covers, Wave Motion, doi:10.1016/j.wavemoti.2016.08.003.
- Wang, Y., B. Holt, E.W. Rogers, J. Thomson, and H.H. Shen (2016) Wind and wave influences on sea ice floe size and leads in the Beaufort and Chukchi Seas during the summer-fall transition 2014, J. Geophys. Res. – Oceans, doi:10.1002/2015JC011349.
- Zhao, X., Shen, HH, Cheng, S. (2015) Modeling ocean wave propagation under sea ice covers. Acta Mech. Sinica 31(1):1-15.