Tests on Effect of Gravity and Soil Density on Soil Cone Index

2013 ◽  
Vol 774-776 ◽  
pp. 528-531
Author(s):  
Rui Yang Shi ◽  
Jian Qiao Li ◽  
Meng Zou ◽  
Ling He ◽  
Shi Chao Fan ◽  
...  
Keyword(s):  
Lunar Regolith ◽  
Axial Direction ◽  
Lunar Soil ◽  
Foreign Object ◽  
Test Bed ◽  
Low Gravity ◽  
Lunar Rover ◽  
Gravity Condition ◽  
Walking Mechanism ◽  
Cone Index

The cone index is one of the important indicators that can describe the comprehensive physical characteristics of lunar regolith. Its closely related to the sink and sideslip of lunar rover and also has widely used in prediction the trafficability, adhesion property, tractive performance of lunar rover. Based on component method, a kind of low gravity simulator, the tiltable test-bed has been built. This study has got the stable low gravity along axial direction and measured the penetration resistance characteristics of JLU-2 in different gravity through tests. The results shows that the gravity environment has an obvious impact on the cone index of lunar soil simulant, CI values reduce with the decreasing of gravity environment. Namely, in the low gravity condition, it shows weaker resistance ability for a foreign object to penetrate into. The result has important application value of prepare, optimize and risk assessment in walking mechanism of lunar rover and the sampling mechanism.

scholarly journals Volcanic history of the Imbrium basin: A close-up view from the lunar rover Yutu

2015 ◽  
Vol 112 (17) ◽  
pp. 5342-5347 ◽  
Author(s):  
Jinhai Zhang ◽  
Wei Yang ◽  
Sen Hu ◽  
Yangting Lin ◽  
Guangyou Fang ◽  
...  
Keyword(s):  
Lunar Regolith ◽  
Landing Site ◽  
Lunar Soil ◽  
Lunar Rover ◽  
Surface Exploration ◽  
Mantle Reservoir ◽  
History Of ◽  
Radar Measurements ◽  
Residual Melt

We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of ∼5 m of the lunar regolith layer and detected three underlying basalt units at depths of 195, 215, and 345 m. The radar measurements suggest underestimation of the global lunar regolith thickness by other methods and reveal a vast volume of the last volcano eruption. The in situ spectral reflectance and elemental analysis of the lunar soil at the landing site suggest that the young basalt could be derived from an ilmenite-rich mantle reservoir and then assimilated by 10–20% of the last residual melt of the lunar magma ocean.

Effects of Load Type on the Mechanical Properties of the JLU Series Lunar Soil Simulant

2012 ◽  
Vol 204-208 ◽  
pp. 479-486 ◽  
Author(s):  
Jian Qiao Li ◽  
Rui Yang Shi ◽  
Meng Zou ◽  
Ling He ◽  
Yan Jing Yang ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Lunar Regolith ◽  
Influence Factors ◽  
Friction Angle ◽  
Lunar Soil ◽  
Strength Characteristics ◽  
Natural State ◽  
Environmental Load ◽  
Lunar Rover

The pressure-sinkage characteristics and the shear-strength characteristics of lunar regolith are the important influence factors to the trafficability of lunar rover. The performance curves and parameters of JLU luanr soil simulant were obtained by pressure-sinkage tests and shear-strength tests in the ground gravity-environmental load (1g) and the lunar gravity-environmental load (1/6g). The results show that, for the pressure-sinkage characteristics, the compression-strength of the JLU-1 is strongest, followed by the JLU-3, and the JLU-2 is the weakest. In different load levels, the deformability index n increases as the bulk density increases. The kc increase as the state becoming more and more compact,The k of JLU-1 is the largest of all, followed by JLU-3 next, JLU-2 has the smallest.The load levels have no significant effect to the tendency of n, kc and k. For the shear-strength characteristics, the shear resistance of JLU-2 is the weakest. JLU-1 has the greatest cohesion c of the three lunar soil simulant, followed by JLU-3, the c of JLU-2 is the smallest.The c of the same lunar soil simulant in natural state is greater than it in soft state. Compared with JLU-1 and JLU-3, JLU-2 has the smallest internal friction angle .The influence of the load levels to the the cohesion c internal friction angel is not obvious. The  mesured in the lunar load is wider than it in the ground load. This study will supply fundamental reference and foundation on the research and optimization of the lunar rover traveling mechanism in the authentic lunar environment.

Research on a Rotary-Percussive Coring Drill for Lunar Exploration

2012 ◽  
Vol 233 ◽  
pp. 297-302 ◽  
Author(s):  
S. Li ◽  
Q. Quan ◽  
De Wei Tang ◽  
S. Jiang ◽  
X. Hou ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Lunar Regolith ◽  
Experimental Tests ◽  
Lunar Soil ◽  
Soil Core ◽  
Test Bed ◽  
Drilling Parameters ◽  
Penetration Ratio ◽  
Rotary Speed ◽  
Exploration Mission

China is launching the Chang'e project to send automated machine for acquiring the lunar soil and returning to the earth. Thus, we are trying to develop a kind of effective mechanism for the exploration mission of lunar soil coring. This paper presents a rotary-percussive coring drill which is a novel scheme for the deep surface soil acquirement. Two degrees of freedom are included in the proposed drill mechanism. Specifically-designed drill unit including auger and drill bit is employed to finish the coring of the simulant of lunar regolith. We have proposed a novel coring concept named soft-bag coring. Since there is no relative motion between the soft-bag and the cut soil core, the soft-bag method may keep the original stratification of lunar soil. A test-bed has been developed to conduct experimental tests under different drilling parameters and circumstances. The related drilling parameters such as rotary speed, penetration ratio, and percussive frequency are adjusted to adapt to different situations in the experiments. The experimental results indicate that the specifically considered drill mechanism with soft-bag inside can get high coring ratio and excellent stratification of the soil.

Estimation of the Strength of the Lunar Soil by the Depth of the Lunar Rover Wheel Tracks

2021 ◽  
Vol 55 (4) ◽  
pp. 285-308
Author(s):  
A. T. Basilevsky ◽  
M. I. Malenkov ◽  
V. A. Volov ◽  
A. M. Abdrakhimov ◽  
N. A. Kozlova ◽  
...  
Keyword(s):  
Lunar Soil ◽  
Lunar Rover

Control of Drilling and Coring Device Based on Online Identification

2013 ◽  
Author(s):  
Qiquan Quan ◽  
S. Li ◽  
S. Jiang ◽  
X. Hou ◽  
Z. Deng
Keyword(s):  
Object Recognition ◽  
Lunar Regolith ◽  
Lunar Soil ◽  
Recognition System ◽  
Current Level ◽  
Support Vector ◽  
Drilling Process ◽  
Operating Modes ◽  
Online Identification ◽  
Lunar Environment

This paper presents a drilling and coring device for the lunar exploration, which is possibly utilized to acquire the lunar regolith with a certain depth. The drilling device is composed of three components: rotary unit, percussive unit and penetrating unit. The rotary-percussion drill can work in two different operating modes: rotary mode and rotary-percussive mode, depending on the properties of cut object. In the relatively loose regolith, rotation and penetration can make the drill work in a well state. However, once rock is encountered in the drilling process, besides rotation and penetration, percussion must be launched to reduce the drilling power and the required penetrating force. Due to the indetermination of the lunar environment, it is not easy to control the coring drill to adapt to the encountered conditions. To obtain a high coring ratio with relatively low power, an intelligent drilling strategy is inevitably proposed to accomplish the drilling process control. Considering the lunar soil simulant should cover the possible composition of real lunar soil, simulant are classified into several levels based on the generalized drillability. For each level of drillability of lunar soil simulant, experiments are conducted to get the characteristics in frequency-domain of rotary torque output. The sampled characteristics of rotary torque output are utilized to train the object-recognition system based on Support Vector Machine (SVM). Information in all the levels of drillability of lunar soil simulant is stored in the object-recognition system as an expert system. To understand the properties of the drilling object, rotary torque is selected to identify the level of drillability of simulant in drilling process. Subsequently, once the level is obtained, drilling strategy is adjusted to adapt to the current level correspondingly in real time. Experiments are conducted to verify the intelligent drilling strategy successfully.

Numerical Simulation on the Instability of Cylindrically Expanding Premixed Flames With Radiative Heat Loss at Low Lewis Numbers

2011 ◽  
Author(s):  
Takafumi Kusakai ◽  
Satoshi Kadowaki
Keyword(s):  
Heat Loss ◽  
Thermal Instability ◽  
Radiative Heat ◽  
Premixed Flames ◽  
Lewis Number ◽  
Radiative Heat Loss ◽  
Low Gravity ◽  
Gravity Condition ◽  
Quenching Condition ◽  
Reactive Gases

The instability of cylindrically expanding premixed flames with radiative heat loss was studied by two-dimensional unsteady calculations of reactive gases, based on the diffusive-thermal model equation. When the Lewis number was unity, instability phenomena were not observed. When the Lewis number was sufficiently low, on the other hand, cellular-shaped fronts on adiabatic and non-adiabatic cylindrical flames were observed, which was due to diffusive-thermal instability. As radiative heat loss increased, the behavior of cellular fronts became more unstable. This indicated that the radiation promoted the unstable behavior of flame fronts at low Lewis numbers. When radiative heat loss was much large compared with the quenching condition of a planar flame, cylindrical flames were broken up and several small flames appeared. This was in qualitative agreement with the experimental results on the dynamic behavior of lean hydrogen-air premixed flames with radiative heat loss under the low gravity condition. Several small flames appeared on the grounds that large curvature of flame fronts was necessary to keep high temperature against radiative heat loss.

Research of Formed Lunar Regholit Analog AGK-2010 / Badania wytworzonego analogu gruntu księżycowego AGK-2010

2013 ◽  
Vol 58 (2) ◽  
pp. 551-556
Author(s):  
Stanisław Bednarz ◽  
Mirosław Rzyczniak ◽  
Andrzej Gonet ◽  
Karol Seweryn
Keyword(s):  
Grain Size ◽  
Shear Strength ◽  
Oil And Gas ◽  
Lunar Regolith ◽  
Lunar Soil ◽  
Research Centre ◽  
Mechanical Parameters ◽  
The Moon ◽  
The Cost ◽  
Academy Of Sciences

The results investigations of a soil having similar properties as lunar regolith performed at the Department of Drilling and Geoengineering, Faculty of Drilling, Oil and Gas, AGH University of Science and Technology in Kraków are presented in this paper. The research was carried out jointly with the Space Research Centre, Polish Academy of Sciences in Warsaw. The objective of the cooperation was to minimize the cost of tests of penetrator KRET, which will be used on the surface of the Moon. The American lunar regolith (e.g. CHENOBI) was used as reference soil. The most important properties were presented graphically in the form of figures and tables: grain size distribution, selected physical properties (bulk density, colour), selected mechanical parameters (shear strength, inner friction strength, cohesion). As a result the first Polish lunar soil analog AGK-2010 was produced.

Thermal conduction in a composite circular cylinder: a new technique for thermal conductivity measurements of lunar core samples

1980 ◽  
Vol 293 (1406) ◽  
pp. 571-598 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Conduction ◽  
Lunar Regolith ◽  
Lunar Soil ◽  
New Technique ◽  
Conductivity Measurements ◽  
Core Samples ◽  
Present Technique ◽  
A New Technique ◽  
Lunar Core

A new technique has been developed for the measurement of the thermal conductivity of lunar core samples. According to this technique, the core sample is heated radiatively from the outside at a known rate, the temperature is measured at the surface of the coretube, and the thermal conductivity of the sample is determined by comparing the measured temperature with the theory. The technique conforms with the aims of lunar sample preservation in that the sample remains intact after the measurements. The solution, as obtained in this paper, of a thermal conduction equation for a composite circular cylinder, with zero initial temperature and a constant heat-flux at its outer boundary, provides a theoretical basis for the present technique. Because of their mathematical similarity, the corresponding problems for a composite slab or sphere were also solved and the solutions are presented for possible future application to the thermal conductivity measurements. Testing demonstrated the feasibility of the new technique. The thermal conductivity of a simulant lunar soil sample, as determined by the present technique under vacuum conditions at about 300 K for sample densities of 1.47-1.67 g cm -3 , is 2.05-2.65 x 10 -3 W m -1 K -1 , which compares favourably with that of the same sample, 1.61-2.89 x 10 -3 W m -1 K -1 at sample densities of 1.50-1.75 g cm -3 , as measured under similar conditions by the standard line heat source technique. We describe in detail the experimental apparatus construction and procedure; in particular, the number of precautions taken to preserve the samples from disturbances and to improve the measurement results. This technique was successfully applied to the thermal conductivity measurement of two Apollo 17 drill-core samples. The results, 1.9-4.9 x 10 -3 W m -1 K -1 , which is intermediate between the values of thermal conductivity of the lunar regolith determined in situ (0.9-1.3 x 10 -2 W m -1 K -1 and those of lunar soil samples measured in the laboratory under simulated lunar surface conditions (0.8-2.5 x 10 -3 W m -1 K -1 ) presents an important clue to the understanding of heat transportation mechanisms in the lunar regolith.

Analysis on the Movement Effect of Lunar Rover Wheel

2013 ◽  
Vol 307 ◽  
pp. 211-214 ◽  
Author(s):  
Da Wei Jin ◽  
Jian Qiao Li ◽  
Shi Chao Fan ◽  
Hao Li ◽  
Yang Wang
Keyword(s):  
Lunar Soil ◽  
Test Results ◽  
Lunar Rover ◽  
Movement Effect ◽  
Motion Resistance ◽  
Soil Bin ◽  
Passing Ability ◽  
Drawbar Pull ◽  
Driving Torque

It is important to analyze mechanical relationship between lunar wheel and lunar soil for studying passing ability of regolith in lunar soil. Mechanical relationship between lunar wheel and regolith could be reflected by these parameters such as sinkage, drawbar pull, driving torque, motion resistance and slip when the lunar wheel moves. Thus, it is necessary to analyze these parameters of lunar wheel by soil bin test. The test results show that, the four parameters increase with slip and loading, except motion resistance of the test wheel which is under 70N at the speed of 25mm/s. The variations of the four parameters are not significantly influenced by velocity. The variations of the four parameters are significantly influenced by loading.

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