Microgravity combustion of polyethylene droplet in drop tower

2020 ◽  
Vol 222 ◽  
pp. 18-26 ◽  
Author(s):  
Peiyi Sun ◽  
Chuanjia Wu ◽  
Feng Zhu ◽  
Shuangfeng Wang ◽  
Xinyan Huang
Keyword(s):  
Drop Tower ◽  
Microgravity Combustion

scholarly journals The Drop Tower Bremen

2010 ◽  
Vol 22 (4) ◽  
pp. 461-461 ◽  
Author(s):  
M. Dreyer
Keyword(s):  
Drop Tower

Microgravity combustion of isolated n-decane and n-heptane droplets

1992 ◽  
Author(s):  
MUN CHOI ◽  
FREDERICK DRYER ◽  
JOHN CARD ◽  
FORMAN WILLIAMS ◽  
JOHN HAGGARD ◽  
...  
Keyword(s):  
Microgravity Combustion

scholarly journals Photophoretic forces on chondrules in drop tower experiments

2011 ◽  
Vol 327 ◽  
pp. 012044
Author(s):  
A Hesse ◽  
J Teiser ◽  
G Wurm
Keyword(s):  
Drop Tower

scholarly journals Drop-tower experiments for capillary surfaces in an exotic container

AIAA Journal ◽  
1992 ◽  
Vol 30 (1) ◽  
pp. 134-137 ◽  
Author(s):  
Paul Concus ◽  
Robert Finn ◽  
Mark Weislogel
Keyword(s):  
Drop Tower ◽  
Capillary Surfaces

Blast Mitigation Seat Analysis: Evaluation of Lumbar Compression Data Trends in 5th Percentile Female Anthropomorphic Test Device Performance Compared to 50th Percentile Male Anthropomorphic Test Device in Drop Tower Testing

2016 ◽  
Author(s):  
Kelly Bosch
Keyword(s):  
Lumbar Spine ◽  
Vertical Direction ◽  
Drop Tower ◽  
Blast Mitigation ◽  
Test Device ◽  
Military Population ◽  
Data Set ◽  
System Survivability ◽  
Blast Energy ◽  
Hybrid Iii

Although blast mitigation seats are historically designed to protect the 50th percentile male occupant based on mass, the scope of the occupant centric platform (OCP) Technology Enabled Capability Demonstration (TEC-D) within the U.S. Army Tank Automotive Research Development Engineering Center (TARDEC) Ground System Survivability has been expanded to encompass lighter and heavier occupants which represents the central 90th percentile of the military population. A series of drop tower tests were conducted on twelve models of blast energy-attenuating (EA) seats to determine the effects of vertical accelerative loading on ground vehicle occupants. Two previous technical publications evaluated specific aspects of the results of these drop tower tests on EA seats containing the three sizes of anthropomorphic test devices (ATDs) including the Hybrid III 5th percentile female, the Hybrid III 50th percentile male, and the Hybrid III 95th percentile male. The first publication addressed the overall trends of the forces, moments, and accelerations recorded by the ATDs when compared to Injury Assessment Reference Values (IARVs), as well as validating the methodology used in the drop tower evaluations1. Review of ATD data determined that the lumbar spine compression in the vertical direction could be used as the “go/no-go” indicator of seat performance. The second publication assessed the quantitative effects of Personal Protective Equipment (PPE) on the small occupant, as the addition of a helmet and Improved Outer Tactical Vest (IOTV) with additional gear increased the weight of the 5th percentile female ATD more than 50%2. Comparison of the loading data with and without PPE determined that the additional weight of PPE increased the overall risk of compressive injury to the lumbar and upper neck of the small occupant during an underbody blast event. Using the same data set, this technical paper aimed to evaluate overall accelerative loading trends of the 5th percentile female ATD when compared to those of the 50th percentile male ATD in the same seat and PPE configuration. This data trend comparison was conducted to gain an understanding of how seat loading may differ with a smaller occupant. The focus of the data analysis centered around the lumbar spine compression, as this channel was the most likely to exceed the IARV limit for the 5th percentile female ATD. Based on the previous analysis of this data set, the lightest occupant trends showed difficulty in protecting against lumbar compression injuries with respect to the 5th percentile female’s IARV, whereas the larger occupants experienced fewer issues in complying with their respective IARVs for lumbar compression. A review of pelvis acceleration was also conducted for additional kinetic insight into the motion of the ATDs as the seat strokes. This analysis included a review of how the weight and size of the occupant may affect the transmission of forces through a stroking seat during the vertical accelerative loading impulse.

Effects of Lumbar Spine Assemblies and Body-Borne Equipment Mass on Anthropomorphic Test Device Responses During Drop Tests

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Daniel Aggromito ◽  
Mark Jaffrey ◽  
Allen Chhor ◽  
Bernard Chen ◽  
Wenyi Yan
Keyword(s):  
Lumbar Spine ◽  
Federal Aviation Administration ◽  
Relative Displacement ◽  
Drop Tower ◽  
Test Device ◽  
Hybrid Iii ◽  
Drop Tests ◽  
Occupant Injury ◽  
Maximum Relative Displacement ◽  
The Impact

When simulating or conducting land mine blast tests on armored vehicles to assess potential occupant injury, the preference is to use the Hybrid III anthropomorphic test device (ATD). In land blast events, neither the effect of body-borne equipment (BBE) on the ATD response nor the dynamic response index (DRI) is well understood. An experimental study was carried out using a drop tower test rig, with a rigid seat mounted on a carriage table undergoing average accelerations of 161 g and 232 g over 3 ms. A key aspect of the work looked at the various lumbar spine assemblies available for a Hybrid III ATD. These can result in different load cell orientations for the ATD which in turn can affect the load measurement in the vertical and horizontal planes. Thirty-two tests were carried out using two BBE mass conditions and three variations of ATDs. The latter were the Hybrid III with the curved (conventional) spine, the Hybrid III with the pedestrian (straight) spine, and the Federal Aviation Administration (FAA) Hybrid III which also has a straight spine. The results showed that the straight lumbar spine assemblies produced similar ATD responses in drop tower tests using a rigid seat. In contrast, the curved lumbar spine assembly generated a lower pelvis acceleration and a higher lumbar load than the straight lumbar spine assemblies. The maximum relative displacement of the lumbar spine occurred after the peak loading event, suggesting that the DRI is not suitable for assessing injury when the impact duration is short and an ATD is seated on a rigid seat on a drop tower. The peak vertical lumbar loads did not change with increasing BBE mass because the equipment mass effects did not become a factor during the peak loading event.

Drop tower ‘bremen’: A weightlessness laboratory on earth

Endeavour ◽  
1991 ◽  
Vol 15 (2) ◽  
pp. 72-78 ◽  
Author(s):  
Hansjörg Dittus
Keyword(s):  
Drop Tower
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