Multi-scale Investigation of sediment transport processes in geophysical flows
EMI Conveners: Manousos Valyrakis, Rui ML Ferreira, Mário Franca
Transport of sediments in geophysical flows occurs in mountainous, fluvial, estuarine, coastal, aeolian and other natural or man-made environments on Earth and has been shown to play important formative roles in planets and satellites such as Mars, Titan, and Venus. Understanding the motion of sediments is still one of the most fundamental problems in hydrological and geophysical sciences. Such processes can vary across a wide range of scales - from the particle to the landscape - which can directly impact both the form (geomorphology) and, on Earth, the function (ecology and biology) of natural systems and the built infrastructure surrounding them. In particular, feedback between flow and sediment transport as well as interparticle interactions including size sorting are a key processes in surface dynamics, finding a range of important applications, from hydraulic engineering and natural hazard mitigation to landscape evolution and river ecology.
Specific topics of interest include (but are not restricted to):
particle-scale mechanics of entrainment and disentrainment
Discrete element modelling of granular processes and upscaling into continuum frameworks
upscaling and averaging techniques for stochastic processes related to granular processes
interaction among grain sizes in poorly sorted mixtures, including particle segregation
momentum/energy transfer between turbulent flows and particles
derivation and solution of equations in particular for multiphase flows
reach scale sediment transport and geomorphic processes
shallow water hydro-sediment-morphodynamic processes
fluvial processes in response to reservoir operation schemes
7. Instrumentation in river engineering and monitoring of geomorphic processes
EMI Conveners: Rui ML Ferreira, Manousos Valyrakis
Advances in hardware and software have widened the range of tools and methods available to measure key flow variables in fluvial and other natural or built environments. Nowadays, a range of laser (3D LDV, stereo-PIV), acoustic (ADV, ADCP, ABS) and ultrasonics (UVP), are typically deployed towards obtaining flow field variables, at a high spatiotemporal resolution. In addition, stone tracing (RFID), particle instrumentation (MEMS) and optical methods (PTV, LSPIV), allow from directly assessing particle transport to indirectly measuring flow field quantities. Laser-based scanning methods and advances in photogrammetry (structure from motion) are commonly used to reconstruct detailed riverbed morphologies and water surface geometries.
This session aims at bringing together researchers developing or using non-intrusive flow measuring techniques, including but not limited to the methods described above, finding a breadth of important applications, from the micro to the reach scale, in virtually all fields of river hydraulics and environmental fluid mechanics.
BS2: Measurements and instrumentation in hydraulic engineering
EMI Conveners: Manousos Valyrakis, Rui ML Ferreira, Massimo Guerrero,
Advances in hardware and software, as well as conceptual advances, have widened the range of tools and methods available to measure key flow variables in fluvial and other natural or built environments. Nowadays, a range of laser (3D LDV, stereo-PIV), acoustic (ADV, ADCP, ABS) and ultrasonics (UVP) are typically deployed towards obtaining flow field variables, at an unprecedented spatiotemporal resolution, expanding the range of scales and applications, driving our understanding of fundamental dynamical flow and transport processes as well as leading to improved engineering designs. For instance, geomorphology and environmental hydraulics researchers, as well as engineering practitioners, customarily deploy established velocimetry methods such as ADV or PIV to retrieve all three components of the velocity field at a high space and time resolution. Optical flow methods are increasingly used by industrial flow communities along with LDA/LDV and ultrasound velocimetry. Acoustic techniques (such as UVP or ADCP) enable the investigation of velocity fields along with sediment transport in harsh conditions, especially where turbidity may hinder optical-laser penetration. The domain of application continues to expand from the micro-scale (e.g. eco-biological and industrial applications in the field of micro-fluidics) to river reach scales and coastal areas (in the case of planar LSPIV and ADCP-ABS). Pressure can be derived from time-resolved 3D PIV while data assimilation techniques allow for hybrid experimental-numerical flow descriptions with higher temporal or spatial resolutions. Laser-based methods can be used to reconstruct detailed bed surface morphologies, while advances in photogrammetry and 3D scanning enable the reconstruction of detailed bathymetries of channels and free-surface profiles. In addition, stone tracing (RFID), particle instrumentation (MEMS) and optical methods (PTV, LSPIV which can also be drone-enabled), allow from directly assessing particle transport rate and identifying its dynamics, to indirectly measuring flow field quantities.
This session is promoted by the IAHR committee of Experimental Methods and Instrumentation and aims at bringing together researchers developing or using non-intrusive flow measuring techniques, including but not limited to the methods described above, finding a breadth of important applications.
A selection of the most impactful papers will be published in a special issue of a Scopus indexed journal. Conveners are planning to organise a special issue in Advances in Water Resources.