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Abstract The Multi-terrain Amphibious ARCtic explOrer (MAARCO) rover is an amphibious arctic rover designed to explore arctic regions in otherwise unsafe or restricted environments. The MAARCO rover consists of a propulsion system with two helical drives made up of hollow cylinder ballasts wrapped in auger or screw shaped blades that provide thrust to propel the vehicle as the drives rotate. Computational fluid dynamic methods provide a better understanding of the helical drives properties effects on hydrodynamic forces. In this paper, the computational fluid dynamic simulations are performed in ANSYS Fluent to observe the hydrodynamic properties of a helical drive. The drag and thrust on the helical drives are simulated for various helical drives with different blade heights and pitch lengths to determine general trends and characteristics of helical drives in water to optimize the vehicle’s abilities to navigate underwater. The helical drive drag is simulated using bluff body drag simulations with a prescribed velocity. The helical drive thrust is simulated using a multi-reference frame (MRF) mesh model with a frame motion replicate flow rotating around a stationary helical drive at a prescribed angular velocity. A convergence study was conducted to test different meshes and turbulence models to determine the most accurate drag and thrust simulation methods. The results demonstrate the effects the blade height and pitch length have on the helical drive thrust and drag properties, while maintaining a constant ballast diameter. From these results a helical drive design can be determined to optimize the net force and therefore the overall vehicle performance.
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Heliphyrin: a ring open porphyrinoid with helical chirality
We report the template-based synthesis of a new series of ring-open phthalocyanine analogs that exhibit helical chirality. These conjugated helical porphyrinoids also strongly absorb across the entire visible spectrum.
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- Award ID(s):
- 2153081
- PAR ID:
- 10512027
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Inorganic Chemistry Frontiers
- ISSN:
- 2052-1553
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d4qi00743c
