TY - JOUR
T1 - Low-density multi-fan wind tunnel design and testing for the Ingenuity Mars Helicopter
AU - Veismann, Marcel
AU - Dougherty, Christopher
AU - Rabinovitch, Jason
AU - Quon, Amelia
AU - Gharib, Morteza
N1 - Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/9
Y1 - 2021/9
N2 - Prior to its successful flights on Mars, the Ingenuity Mars Helicopter system underwent extensive flight dynamics testing in the 25-ft Space Simulator facility, a low pressure environmental chamber at NASA’s Jet Propulsion Laboratory (JPL), which can re-create relevant Martian conditions on Earth. This facility, while large, is not large enough for free or tethered forward flight tests. In this work, an open-jet, multi-fan wind tunnel concept is presented, which was integrated into the JPL facility to simulate the external freestream flow of forward flight scenarios in a low-density environment. A theoretical and experimental analysis was performed to evaluate the possibility of utilizing commercially available 80 x 80 mm axial flow cooling fan units for this type of wind tunnel. Sub-scale tests found that under Martian conditions, fans deliver approximately 30% reduced flow rates for the same RPM compared to Earth conditions due to decreased efficiencies at low Reynolds numbers. However, fans can run at higher RPM in low-density fluids, with the RPM increase being specific to the fan motor. While power consumption dropped by more than 90%, fans experienced higher thermal loads due to reduced heat convection. The study concludes that the investigated type of cooling fan can operate without modification in a low-density environment, offering a low-cost and easily adaptable wind tunnel solution. Informed by ambient flow field measurements on a comparable multi-fan wind tunnel, a low-density full-scale facility with 441 individually controlled fan units was constructed and used for aerodynamic testing of an engineering model of Ingenuity. Graphic abstract: [Figure not available: see fulltext.].
AB - Prior to its successful flights on Mars, the Ingenuity Mars Helicopter system underwent extensive flight dynamics testing in the 25-ft Space Simulator facility, a low pressure environmental chamber at NASA’s Jet Propulsion Laboratory (JPL), which can re-create relevant Martian conditions on Earth. This facility, while large, is not large enough for free or tethered forward flight tests. In this work, an open-jet, multi-fan wind tunnel concept is presented, which was integrated into the JPL facility to simulate the external freestream flow of forward flight scenarios in a low-density environment. A theoretical and experimental analysis was performed to evaluate the possibility of utilizing commercially available 80 x 80 mm axial flow cooling fan units for this type of wind tunnel. Sub-scale tests found that under Martian conditions, fans deliver approximately 30% reduced flow rates for the same RPM compared to Earth conditions due to decreased efficiencies at low Reynolds numbers. However, fans can run at higher RPM in low-density fluids, with the RPM increase being specific to the fan motor. While power consumption dropped by more than 90%, fans experienced higher thermal loads due to reduced heat convection. The study concludes that the investigated type of cooling fan can operate without modification in a low-density environment, offering a low-cost and easily adaptable wind tunnel solution. Informed by ambient flow field measurements on a comparable multi-fan wind tunnel, a low-density full-scale facility with 441 individually controlled fan units was constructed and used for aerodynamic testing of an engineering model of Ingenuity. Graphic abstract: [Figure not available: see fulltext.].
UR - http://www.scopus.com/inward/record.url?scp=85114041398&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85114041398&partnerID=8YFLogxK
U2 - 10.1007/s00348-021-03278-5
DO - 10.1007/s00348-021-03278-5
M3 - Article
AN - SCOPUS:85114041398
SN - 0723-4864
VL - 62
JO - Experiments in Fluids
JF - Experiments in Fluids
IS - 9
M1 - 193
ER -