航空学报论文模板

Contents lists available at ScienceDirectChinese Journal of Aeronauticsjournal homepage: /locate/cjaChinese Journal of Aeronautics 24 (2011) xx-xxGeneration of Dynamic Grids and Computation of UnsteadyTransonic Flows around AssembliesCAI Fei a,*, ZHANG Liping ba Department of Aerodynamics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, Chinab School of Electronic and Information Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, China（投稿时请将作者姓名和单位删掉）(注：英文单位名称请注意写准确，具体可上本刊网站下载中心“单位英文名称”查询，如发现本刊所给英译文有误，欢迎指正)Received 5 May 2009; revised 11 June 2009; accepted 16 September 2009AbstractThe coupled numerical simulation of flow field, solid temperature field, species concentration field and gas radiation transfer/ energy field based on statistical narrow-band correlated-k (SNBCK) model, is employed to accurately predict aerothermodynamic characteristic of aircraft exhaust system. A series of methods to increase computational efficiency and descend computational resources make it possible to finish the calculation in PC. The parameters of narrow-band model are evaluated by HITEMP line-by-line database. Three examples have proved the accuracy of using these methods to solve flow heat transfer coupled prob-lem and radiation transfer/energy equation, which are the calculation of temperature distribution of water-cooling nozzle in rock-et engine, the calculation of carbon dioxide absorptivity at 4.3 micron band, and the gas radiation heat transfer evaluation of the cylindrical furnace. Finally, the inner flaps temperature distribution of ejecting nozzle with floating outer flaps is computed, un-der high-altitude, high-speed and afterburning conditions. Two completely different air-inlet schemes of ejecting channel almost achieve the same effect in cooling inner flaps.（英文摘要应不少于150词；包含研究的目的、方法、结果和结论；通常用一般现在时，除非有明显的过去时间指示词出现）Keywords:transonic flow; unsteady flow; full-potential equation（5-8个，建议其中1-2个选自EI controlled term 词表）1. IntroductionThe computation method of unsteady transonic flow based on N-S equations should be best accurate, but to three-dimensional complex problems, it can be achieved only on large computers, and moreover, the results are not ideal sometimes[1]. A viscous/inviscid *Corresponding author. Tel.: +86-10-82317058.E-mail address: abc@Foundation item: National Natural Science Foundation of China (基金号) （注：基金项目的正确英文名称请查询本刊下载中心“基金项目英文名称”）1000-9361/$ - see front matter © 2011 Elsevier Ltd. All rights reserved. doi:interaction method is an applicable one and the com-putation time can be reduced by two orders.The method to solve the full-potential equation over transonic unsteady forces on wings has been devel-oped[2-3], but to assemblies, it is not mature, and the research works are continuously carried on[4-5].The key to compute the unsteady aerodynamic forc-es is to generate dynamic grids efficiently. In the pre-sent paper, an algebraic method and rapid deforming technique are used to generate three-dimensional boundary-fitted dynamic grids for assemblies. The conservative full-potential equation is solved by a time-accurate approximate factorization algorithm and internal Newton iterations. An integral boundary layer method based on the dissipation integral is used to ac-count for viscous effects. The computational results about unsteady transonic forces on wings, bodies and control surfaces are in agreement with experimental data. （前言一般不要放图、表、公式） 2. Computation Scheme 2.1. Governing equationThe unsteady full-potential equation written in a body fitted coordinate system is given by()()()()0U V W τξηζρρρρ+++=J J J J(1)where ρ is density, U , V , and W are the contravariant velocity components in the ξ, η, and ζ direc-tions,τmeans time, and J is Jacobian. （正文中不要用公式编辑器插入符号，直接敲入即可）2111213122223132333()()()t t t t t t q U V W U a a a V a a a W a a a ξηζξηζξηζξηζξφηφζφξφφφηφφφζφφφ⎧=-+-+-⎪=+++⎪⎨=+++⎪⎪=+++⎩ （公式编辑器中的行距不要改动，默认值即可） (公式中用到小括号时，不要用公式编辑器中的括号，如()x ，直接用键盘敲入即可如()x ) where φ is velocity potential. 2.2. Generation of gridsThe algebraic method is used to generate three-dimensional boundary-fitted grids for a wing. The height of the first grid next to the body is con-trolled, and the grids near to the body are normalized. To wing/missile combination, the H-H boundary- fitted grids for a single wing are generated at first in order to simulate the aerodynamic forces on missiles accurately. The section at the position of pylon is changed into two overlapping layers. A partial deform-ing technique is used in the area of pylon/launching/ missile to get the static grids for the combination.When with fuselage, the deforming technique is used at the symmetric section to get the static grids also. To simplify the equation, the dynamic grids where the far field is fixed and the body is dynamic are ap-plied to unsteady flows. As it will consume much time to generate grids once a time-step, to aerodynamic elasticity movement of small amplitude, ordinarily, the grids are obtained by solving the balance equation based on last time-step, but that is still not economic. Taking the incompressible potential flow round a cylinder for example, the stream function is2sin a V r r ψθ∞⎛⎫=-⎪⎝⎭(2) where a is radius, V ∞ is the velocity of free stream. Magnifying its radius to a ε+, then the previous streamline passing point (r , θ ) will yield a normal dis-placement ∆r()222r a r r a εε-∆=-⋅+ (3)That is difficulty directly to generate dynamic grids. Simplifying further, the coordinates (represented by subscript u ) of the dynamic grids ares ()u r r g =--⋅x x x x (4)where subscript s represents the boundary-fitted static grids which are used as the initial values, r represents the instantaneous coordinate that the static grids move to with bodies, g is the function about the serial num-ber of the grid lines.222b b bf b f b f b max ,,i i j j k kg i i j j k k ⎛⎫⎛⎫⎛⎫⎛⎫--- ⎪= ⎪ ⎪ ⎪ ⎪---⎝⎭⎝⎭⎝⎭⎝⎭ (5)where b represents the corresponding boundary points,f represents the far field points. 3. Presentation of ResultF5 wing/missile and HARW wing/fuselage are taken for examples in the present paper. Fig.1 shows the sketches of F5 wing/missile and HARW wing/fuselage with control surfaces. The missile is located at 73.5 percent of half-span. The trailing edge control surface of HARW wing/fuselage takes up 20 percent of the chord; control surface I is located at a position from 58.9% to 79.4% of half span; control surface II is lo-cated from 9.6% to 23.9%. Fig.2 is the H-H surface grids for F5 wing/missile. Fig.3 shows the overlooking view of HARW wing/fuselage assem bles’ C -H grids.Fig.4 Comparison between computation result and experi-mental data [24] for temperature distribution of inner wall of nozzle.Table 5 CPU time ratio of each termComputational term CPU time/%Flow field 32.6Solid temperature field 2.2Species concentration field 4.3Radiation transfer/energy field 60.94. Conclusions(1) A rapid method of the generation of bounda-ry-fitted dynamic grids is developed in this paper, and the method of Viscous/Inviscid Interaction is used to compute the unsteady aerodynamic forces on wing/missiles and wing/body with control surfaces. (2) The computation results are in agreement with experimental data. To unsteady flows, it takes nearly one hour to carry out three time cycles with 140 thou-sand nodes, so this method is powerful. This method presented in this paper provides an applicable, efficient tool for the aerodynamic elasticity analysis in the tran-sonic aspect. （分点总结，只写结论，其他背景、方法都不必赘述）References[1]Matthews F L, Rawlings R D. Composite materialsengineering and science. 2nd ed. New York: Chapman& Hall, 1994.（专著）[2]Soutis C, Fleck N A. Static compression failure of car-bon fibre T800/924C composite plate with single hole.Journal of Composite Materials 1990; 24(5): 536-538.（期刊论文）[3]Bassler H J, Eifler D. Characterisation of plasticityinduced martensite formation during fatigue of austen-itic steel. In: Rie K T, Portella P D. Low-cycle Fatigueand Elasto-plastic Behaviour of Materials. Amsterdam:Elsevier Sci Ltd, 1998; 235-240.（专著中的部分文献）[4]Prairie R R, Zimmer W J. Statistical modeling for par-ticle impact noise detection testing. IEEE ProceedingsAnnual Reliablity and Maintainability Symposium.2004; 536-540.（会议论文）[5]Chadrasear R, Tiwari S N. Thermochemical nonequi-librium and radiative interactions in supersonic hydro-gen-air combustion. AIAA-1992-0340, 1992. （研究报告）[6]RTCA DO-245A. Minimum aviation systems per-formance standards for local area augmentation sys-tem(LAAS). Washington D.C.: RTCA Inc., 2004. （技术规范或标准文献）[7]Barbante P E. Accurate and efficient modeling ofhigh-tempera- ture nonequilibrium air flows. PhD the-sis, von arman Institute for Fluid Dynamics, 2001.（学位论文）[8]Aha D, Murphy P. UCI Repository of machine learningdatabases. </...>. Irvine, CA: University of California, Department of Information and Computer Science, 1994.（电子文献）[9]Khalifa H E, Glauser M N.Low-mixing nozzle for per-sonal ventilation. US Provisional Patent Application No.60/826,929, 2006.（专利文献）注意: 上述文献如为中文文献，则只需提供其英译文，最后加上“[in Chinese]”，其他格式同前。