Thermal Characteristics of Lunar Surface Roughness

1972 ◽  
pp. 269-299
Keyword(s):  
Surface Roughness ◽  
Lunar Surface ◽  
Thermal Characteristics

Numerical Investigation on Simultaneous Effects of Surface Roughness and Variable Properties on Laminar Flow in Annular Tubes

2018 ◽  
Author(s):  
Morteza Heydari ◽  
AmirHossein Bagheri ◽  
Hamid Sadat ◽  
Huseyin Bostanci ◽  
Seifollah Nasrazadani
Keyword(s):  
Surface Roughness ◽  
Thermal Characteristics ◽  
Maximum Velocity ◽  
Nanofluid Flow ◽  
Constant Property ◽  
Nusselt Numbers ◽  
Smooth Channel ◽  
Thermo Physical Properties ◽  
Annular Tube ◽  
Comprehensive Study

A comprehensive study is conducted to evaluate the heat transfer characteristics of laminar nanofluid flow in an annular tube. Thermo-physical properties of the nanofluid is considered to be variable and for the inner and outer walls, there exists serrated surface roughness. The study focuses on the velocity distribution, friction factor and Nusselt number. All results are compared with those for the smooth channel and constant property nanofluid as well. The results show that the tube with serrated wall experiences greater maximum velocity. Moreover, decrease in velocity gradient and some other thermal characteristics result in decrease in average Poiseuille and Nusselt numbers for the rough tube with variable-property fluid.

Lunar surface temperatures and thermal characteristics: Surveyor 5 science results

1968 ◽  
Vol 73 (22) ◽  
pp. 7209-7219 ◽  
Author(s):  
J. W. Lucas ◽  
R. R. Garipay ◽  
W. A. Hagemeyer ◽  
J. M. Saari ◽  
J. W. Smith ◽  
...  
Keyword(s):  
Lunar Surface ◽  
Thermal Characteristics ◽  
Surface Temperatures

scholarly journals Lunar Surface Roughness Estimation Using Stereoscopic Data

2009 ◽  
Vol 7 (ists26) ◽  
pp. Pk_29-Pk_34 ◽  
Author(s):  
Tomoyuki YOSHIMATSU ◽  
Akira IWASAKI ◽  
Junichi HARUYAMA ◽  
Makiko OHTAKE ◽  
Tsuneo MATSUNAGA
Keyword(s):  
Surface Roughness ◽  
Lunar Surface ◽  
Surface Roughness Estimation

High Speed Routing of Woven Carbon Fiber Reinforced Epoxy Laminates

2012 ◽  
Author(s):  
M. Meshreki ◽  
A. Sadek ◽  
M. H. Attia
Keyword(s):  
Surface Roughness ◽  
Carbon Fiber ◽  
Tool Wear ◽  
High Speed ◽  
Thermal Characteristics ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Axial Forces ◽  
Carbon Fiber Reinforced ◽  
Dimensional Errors

Little is known about the high speed routing of Carbon Fiber Reinforced Polymers (CFRP). Most of the work in the literature has focused on the drilling of CFRP. In this paper, an extensive experimental study has been conducted to better understand the dynamic, tribological, and thermal characteristics of high speed milling of CFRPs, in the range of 10,000 to 40,000 rpm (200 to 800 m/min, for 6.35 mm end-mill). The material used was a quasi-isotropic laminate comprising 35 plies of woven graphite epoxy. The tool wear was investigated on the flank and the rake faces. The machined slots were characterized in terms of straightness errors, dimensional errors, surface roughness, and delamination. The tool over-hang controls the tool dynamics, in this high speed range, and significantly affect various quality attributes of the produced holes; roughness, dimensional errors, and straightness. Similar trends were observed for the forces and the temperatures, whereby there is a given speed at which they reach a minimum and then they start to increase for higher speeds. The machining force and temperature trends with varying speeds and feeds are controlled by the chip load, the specific cutting pressures, and the effect of the frictional forces. The increased tool wear was found to directly affect the cutting forces and consequently lead to high delamination and surface roughness. The milled surface quality was mainly controlled by the feed rate. Limited surface delamination was observed due to the low axial forces associated with the routing process.

Lunar surface roughness based on multiscale morphological method

2015 ◽  
Vol 108 ◽  
pp. 13-23 ◽  
Author(s):  
Wei Cao ◽  
Zhanchuan Cai ◽  
Zesheng Tang
Keyword(s):  
Surface Roughness ◽  
Lunar Surface ◽  
Morphological Method

scholarly journals COMPARATIVE STUDY OF LUNAR ROUGHNESS FROM MULTI - SOURCE DATA

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 99-104
Author(s):  
Y. Lou ◽  
Z. Kang
Keyword(s):  
Surface Roughness ◽  
Lunar Surface ◽  
Calculation Method ◽  
Evaluation System ◽  
Landing Site ◽  
Data Sources ◽  
Mean Square ◽  
Complete Evaluation ◽  
Source Data ◽  
Surface Fluctuation

The lunar terrain can show its collision and volcanic history. The lunar surface roughness can give a deep indication of the effects of lunar surface magma, sedimentation and uplift. This paper aims to get different information from the roughness through different data sources. Besides introducing the classical Root-mean-square height method and Morphological Surface Roughness (MSR) algorithm, this paper takes the area of the Jurassic mountain uplift in the Sinus Iridum and the Plato Crater area as experimental areas. And then make the comparison and contrast of the lunar roughness derived from LRO's DEM and CE-2 DOM. The experimental results show that the roughness obtained by the traditional roughness calculation method reflect the ups and downs of the topography, while the results obtained by morphological surface roughness algorithm show the smoothness of the lunar surface. So, we can first use the surface fluctuation situation derived from RMSH to select the landing area range which ensures the lands are gentle. Then the morphological results determine whether the landing area is suitable for the detector walking and observing. The results obtained at two different scales provide a more complete evaluation system for selecting the landing site of the lunar probe.

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