Evaluation and Optimisation of Aeolian Sand Trap Designs

Aeolian sand-trap design plays a critical role in quantifying and interpreting wind-driven sediment transport in coastal and other exposed environments. Traditionally, sand traps have been developed primarily to measure mineral sand fluxes and to mitigate the adverse effects of aeolian transport on infrastructure and landscapes. Aeolian processes also act as an important vector for redistributing organic material, including seeds and other biologically relevant components embedded within the sand environment, which are essential for dune development, vegetation dynamics, and ecosystem resilience. Optimising sand-trap design is therefore necessary not only to accurately capture sand transport rates and directions but also to enable a more representative assessment of the coupled transport of mineral and organic material.

In this study, we assess and optimise aeolian sand trap designs for application along the Lithuanian Baltic Sea coast, with particular focus on the highly dynamic dune systems of the Curonian Spit. Two commonly used designs are evaluated: the Big Spring Number Eight (Fryrear) trap and an omnidirectional cylindrical trap. Their performance is examined under local aeolian conditions using numerical simulations that capture characteristic wind regimes, seasonal variability, and typical sand-grain-size distributions. Airflow modelling and particle trajectory analyses are applied to investigate how trap geometry, inlet configuration, and installation height influence capture efficiency and directional sensitivity.

The sand trap designs are analysed within a computational fluid dynamics (CFD) framework using a finite-volume method (FVM) solver, enabling a detailed assessment of aerodynamic behaviour and sand interception processes. The optimal trap design for long-term monitoring in Lithuanian coastal areas will be chosen and optimised based on the modelling results. These findings will support the development of a field-ready prototype to be deployed as part of an ongoing monitoring programme on the Curonian Spit to detect changes in aeolian transport related to recent shifts in dune vegetation cover. This will also support better coastal management and dune restoration efforts.