دانلود رایگان مقاله لاتین توزیع قطرات در پوشش چتر نجات از سایت الزویر
عنوان فارسی مقاله:
بررسی توزیع قطرات در پوشش چتر نجات حلقه بادبان در باران نور
عنوان انگلیسی مقاله:
Study of droplets distribution on canopy of ringsail parachute in light rain
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Rainfall is a common natural phenomenon. However, when rainfall occurs, the manned space mission which includes rocket launch and spacecraft recovery will be delayed or canceled generally. Especially in the spacecraft recovery, the bad weather is more likely to bring unknown danger because the parachute, which is widely used to supply aerodynamic resistance to the spacecraft recovery, is quite sensitive to the weather conditions. Up to now almost all of the spacecraft recovery activities are carried out in good weather conditions. So it is of great significance to research the effects of rain condition on the performance of parachute for achieving the all-weather implementation of manned space mission. Chinese spacecraft landing area is located in a place where the rainfall is scarce most of the time. Light rainfall has a higher probability of occurrence compared with moderate and heavy rainfall. According to the local rainfall characteristics over the past years, light rain environment is considered in the paper. The research background of the paper can be introduced from the two aspects of ringsail parachute and rain. Ringsail parachute has been widely applied in the aerospace area with its excellent performance. According to existent liter- * Corresponding author. E-mail address: kulouwang126@126.com (J. Yue). atures, ringsail parachute has a better stability than some other types. It is because the gaps between the rings and sails are much more than others while the improved porosity can enhance stability of parachute. Also the ringsail parachute is more popular in the aerospace field due to its rather higher drag coefficient. It can provide enough resistance for the deceleration of re-entry capsule. So far a lot of research on the ringsail parachute has been carried out. Gao and Yu [1] researched the influence of reefing ratio on inflation performance of ringsail parachute and found that the reefing ratio was in linear relationship with the maximum opening load. Yang et al. [2] investigated the influence of permeability of fabric on aerodynamic performance of a ringsail parachute by establishing a new governing equation of flow considering the permeability of fabric. After comparing the numerical results with the traditional results they concluded that the new model was significant to improve the accuracy of flow field simulation. Stein and Tezduyar have achieved great success on the aspect of parachute fluid–structure interaction (FSI) in the past years [3–5]. The FSI modeling of a ringsail parachute for Orion space vehicle was studied in detail by Tezduyar et al. [6] and the results of a special case in which the influence of side winds was included were presented. In fact FSI has always been a focus of researching various types of parachute. Tutt and Taylor [7] used LS-DYNA to numerically simulate the inflation of parachute which was based on the Arbitrary Lagrangian Eulerian (ALE) Method. Kim et al. [8] modeled the evolution of parachute canopy and risers via using the front tracking method on a spring system. In addition there is also some FSI research of parachute and suspension line simulation via the immersed boundary (IB) method [9,10]. Most published literatures on the aspect of any types of parachute are generally aimed at studying the flow field, geometry, material characteristics or FSI problems. Until now, no directly relational literatures on the subject of descent of parachute in light rainfall environment are available
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کلمات کلیدی:
Issues in Biotechnology and Medical Technology Research and ... https://books.google.com/books?isbn=1464964653 2012 - Science Droplets with oil-based adjuvants had more uniform residual distribution in the deposition ... The researchers concluded: “Results of this study demonstrated that ... over the top of the canopy may improve spray distribution across the canopy. Flow and Transport Processes with Complex Obstructions: Applications ... https://books.google.com/books?isbn=1402053851 Yevgeny A. Gayev, Julian C.R. Hunt - 2007 - Science Applications to Cities, Vegetative Canopies and Industry Yevgeny A. Gayev, Julian ... Several relevant mathematical models for such “droplet EPR” are studied in this ... Each of them contributes to the distributed force f in the dispersed droplet ... Rainfall interception and drop sizeÅdevelopment and calibratio https://academic.oup.com/treephys/article-pdf/16/8/727/4687075/16-8-727.pdf by IR Calder - 1996 - Cited by 29 - Related articles Keywords: canopy wetting, drop volume, kinetic energy, Mar- shall-Palmer distribution, rainfall simulator. Introduction. Arguably, the processes controlling the ... Forestry Pesticide Aerial Spraying: Spray Droplet Generation, ... https://books.google.com/books?isbn=9401156344 J.J. Picot, D.D. Kristmanson - 2012 - Technology & Engineering Spray Droplet Generation, Dispersion, and Deposition J.J. Picot, D.D. Kristmanson ... Bergen, J. D. (1979): Aerial spray patterns in a forest canopy, Trans. ... and S. Davie (1980): New Brunswick forestry spray operaions: Field study of effect ... Picot, J.J.C. (1986): Notes on vertical foliage distribution, unpublished, UNB Dept.
