The Sand AbrasioN Device for Aeolian Research (SANDAR): A new experimental device for investigating how wind transport affects sand on Earth and Mars

Wind‐driven dust emission has a major impact on many environmental and socioeconomic issues such as climate change, soil loss, biogeochemical cycles, and air pollution. It is generally assumed that the main global dust sources consist of nonsandy soils with high percentages of fine‐sized clay and silt particles. However, in recent years, it has been hypothesized that active sand bodies can generate significant dust emissions through the mechanism of sand abrasion. Moreover, sand abrasion has been used to explain the formation of certain soils on Earth and Mars. Here, we test the hypothesis that sand abrasion can generate substantial dust emissions by performing targeted wind tunnel experiments on sand grains in the absence of clay and silt particles. We find only minor emissions of particulate matter from noncoated active sands under wind conditions typical of natural sand transport. The findings suggest that the dust generated by the mechanism of sand abrasion is less than dust generated by the removal of clay minerals coated on sand grain surfaces; both mechanisms on active sands produce far less dust than nonsandy soils. Feldspar sand was found to be slightly more effective at generating dust through abrasion than quartz sand. However, due to the low spatial coverage of feldspar sands in active sands worldwide, dust generated from feldspar abrasion may produce a relatively small contribution to global dust emissions. We thus conclude that sand abrasion by wind transport has a low potential to generate dust‐sized particles from active sands.

An abrasive water jet micro-turning experiment device is designed to solve the problem for micromachining the revolving parts. This device is composed of the machine body, hydraulic system, collection devices and control equipment etc. This paper emphasizes on the structure design of the moving parts of the abrasive water jet turning process, clamp, lathe bed, abrasive water jet injecting system and collection system. The turning spindle system and feed drive mechanism are designed, and the strength, stiffness and precision of the ball screw transmission mechanism are calculated and checked to meet the needs of the abrasive water jet micro-turning experiments.

Aeolian processes‐involving erosion, transportation, and deposition of sediment by wind‐occur in a variety of environments including coastal areas, semiarid and arid regions, and agricultural fields. Aeolian processes also occur on some planetary bodies, notably Mars and possibly Venus and on Saturn's moon Titan. Aeolian processes are responsible for the emission and/or mobilization of dust and the formation of areas of sand dunes. Fluctuations in the intensity and geographical extent of wind transport of sediments during the Quaternary have produced an important paleoclimatic record in loess deposits and areas of vegetationstabilized sand dunes.

CFD modelling and validation of measured wind field data in a portable wind tunnel