尾渦流 的英文怎麼說
中文拼音 [wěiguōliú]
尾渦流
英文
eddying wake-
Boeing wants to use existing wing and tail control surfaces that shift up and down about 20 degrees in a coordinated fashion to disrupt the vortical flow
波音公司則利用現成的機翼與機尾控制面,讓它們互相協調、上下移動20度,以擾亂渦流。With the computing program, flow around the square cylinder is resolved at first, and the period of laminar flow is simulated successfully. during the period of vortex street ( re = 100 ), the periodically evolutionary phenomena of the flow behind the square cylinder can be seen
利用計算程序,本文首先對方柱繞流流動進行求解,成功模擬了方柱繞流層流階段的流動和渦街階段( re = 100 )方柱尾流的周期性變化現象。Because wake vortices can persist in calm air for several minutes ( extending for as far as eight miles ), the federal aviation administration requires minimum distances between aircraft, based on size
機尾渦流可以在無風的空氣中停留幾分鐘,向後延伸達12公里,所以美國聯邦航空總署按照飛機大小而規定了飛機之間的最小安全距離。The vortex simulated in this article include the shedding vortex induced by the vane trailing edge boundary layer, the endwall vortex generated by the endwall boundary layer interaction, the passage vortex generated by the rotor rotation, and the leakage vortex generated by the tip clearance flow
渦輪級內的渦運動包括:導向器葉片尾緣附而層引起的脫落渦;轉子通道內轉子的旋轉運動產生的通道渦;根腳區兩個端壁附面層干涉,形成的根腳渦;存在葉尖漏流時,出現的漏流渦。Based on an engineering background, through numerical simulation of the flow field in the hp turbine of the energy efficient engine ( e3 ), the article research the unsteady flow in a transonic turbine stage, the unsteady phenomena in the stage include the shockwave, wake, shedding vortex, endwall vortex, passage vortex and leakage vortex, etc. there are two shockwaves generated on the vane the tailing edge, one on suction side is named moving shockwave, and name another on pressure side steady shockwave
本文首先對于研究的意義和國內外研究的現狀做了簡要的介紹,再從某工程背景出發,通過對e3發動機高壓渦輪內流場的數值模擬,研究了干涉的周期性的問題,以及渦輪級內常見的非定常現象:激波、尾跡、脫落渦、根腳渦、通道渦、漏流渦。導向器尾緣會出現兩道激波,在吸力面的激波可稱為「運動」激波,壓力面的激波可稱為「定常」激波。In this paper, some characteristics of flow movement and sediment transport are analyzed by using the flume experiment data. the cross section of compound channel can be divided into four regions : the undisturbed region in main channel, the interactive region between channel and plain, the undisturbed region in flood plain and the boundary region. in the undisturbed regions, the distribution of longitudinal velocity along the depth has the feature of lograithmic. whereas, in the interactive region, the longitudinal velocity does not obey the logarithmic distribution law, but it can expressed as a revised logarithmic function by using a wake function. on the basis of the kinematic equation the velocity distribution of transverse velocity is obtained. in the boundary region, the longitudinal velocity obeys the law of parabolic distribution. furthermore, according to the simplified diffusion equation, the transverse distribution of sediment concentration in the interactive region is deduced. the analysis is in good agreement with the measured data
本文根據漫灘水流的運動特點,將漫灘水流的復式斷面分為主槽平衡區、灘槽交互區、灘地平衡區及邊壁區等4個區,並給出了各區寬度的經驗公式.根據灘槽交互區垂線流速分佈的變化特點,提出了附加尾流函數的對數流速分佈公式.在簡化水流運動方程和泥沙擴散方程的基礎上,對灘槽交互區內垂線平均流速及含沙量沿橫向分佈進行了理論分析,提出了反映灘槽水流動量交換強度的橫向渦量粘性系數及橫向擴散系數的表達式,得到了漫灘水流垂線平均流速及含沙量沿橫向分佈的解析解,並與實測資料吻合較好Based on the green ' s formula and the assumption of the propeller blade ' s thin sections, a lifting - surface method of propellers with the vortex lattice and equal source panel distributions on the mean camber surface has been introduced for the prediction of steady propeller ' s hydrodynamics in this paper. an approximate kurta condition was applied
基於creen公式和薄翼理論假設導出的升力面方法,採用在螺旋槳拱弧面上分佈離散渦、源布置方法預報均勻流場中的螺旋槳的定常性能,螺旋槳尾渦面上壓力連續性條件採用近似的kutta條件處理。One does this by redistributing the aerodynamic load along the wingspan or by incorporating the vortices coming off the horizontal stabilizer
為了造成這種結果,一個辦法是沿著翼展重新分配空氣動力負載,或是設法利用機尾水平穩定翼所產生的渦流。Eventually mode a and b coexist in the wake, which confirms the previous studies. besides, the present paper finds that downstream the streamwise
從圓柱表面到旋渦形成區、到近尾跡再到下游尾跡流向渦結構從模式a轉換到模式b 、雙渦對模式、再恢復為模式a 。Wake vortex separation standards are used to prevent hazardous wake vortex encounters which mainly found in the final approach course within the airport termination zone. firstly, this paper analysis the mechanism of the vortex decay and research the influence on the safety of the flight ; then. several different radar wake vortex separation standards are compared and some basic guidelines are developed to establish the future vortex standards. in addition, one kind of advance vortex classification for the civil airplane is proposed. secondly, an encounter hazard model which established for the following aircraft and a simple vortex decay model which mostly concern with the proceeding one are developed ; and a safe separation model can be derived from the both. finally, through the simulation calculation, the correctness of the vortex classification of different types of aircrafts are tested and proved
本課題對雷達管制條件下的最小尾流間隔標準進行了較為詳細的分析和研究;首先對尾流的形成和消散機理以及尾流對飛行安全的影響做出了詳細的分析,然後就目前實行的幾種不同的最小尾流間隔標準進行了比較和分析,提出了相關的幾條準則和一種改進的機型尾流分類標準;在這之後,採用理論分析和統計數據分析相結合的方法,建立了尾流危險遭遇基本模型和尾渦消散模型;並在此基礎上對民用航空不同機型的尾流分類的合理性進行了計算和評估,為最小尾流間隔標準的確定和改進提供了初步的理論依據。Large eddy simulation of gas - particle two phase turbulence was carried out, such as simulation of two - dimensional gas - particle two phase wake, two - dimensional gas - particle two phase jet and three - dimensional gas - particle two phase rectangular jet. in these works, les was adopted to simulate gas phase flow and lagrangian approach was utilized to simulate the particles " motion. a series of significant and interesting results were obtained
文中對二維氣粒兩相平面尾跡流場、二維氣粒兩相平面射流流場以及三維氣粒兩相矩形射流流場中的氣相流場進行了大渦模擬、對顆粒運動擴散採用lagrangian模擬研究后,取得了一系列具有重要的理論意義和實際意義的研究成果。And then simulations of gas - particle two phase plane wake and gas - particle two phase plane jet were carried out by using this model. after numerical simulations of the two flow fields were finished, series of analytical work was done. first, the distribution of time - averaged velocity, turbulence intensity was analyzed, and some of the simulation results were compared with those of the experiments ; the coherent structure of vortices in the near wall region of the plane wake flow were studied by describing the evolution of the eddy structures, including the forming, developing and shedding from the wall of the vortices in the near wall region ; the coherent structure of vortices in the whole field was also studied, such as the forming, developing, moving, pairing and merging of the eddies etc.
在對上述兩種流動形態的二維大渦模擬研究中,首先全面地分析了氣相時均流場的速度、湍流強度的分佈規律以及氣相速度的脈動規律等並就部分數值模擬結果與實驗結果進行了對比研究;分析了平面尾跡流場中近壁處旋渦擬序結構,全面和逼真地反映了近壁處旋渦的生成、發展和脫落的規律;描述分析了平面尾跡流和平面射流的全場流動旋渦擬序結構,從整個流場的角度反映旋渦的生成、發展、運動以及旋渦之間相互配對、合併的作用規律等。The complex vortex system structure and shock wave system structure inside this rotor is obtained. wall flow patterns on the blade surface and hub surface are found out. the complex vortex system structure, such as horseshoe vortex, passage vortex, corner vortex and trailing vortex, and the interaction with shock wave system are researched. especially, the character of the tip clearance flow inside the rotor passage is revealed, and the interaction between shock wave and tip clearance flow near blade tip and the evolution of tip clearance flow are considered
給出了葉片表面及輪轂面上的壁面流型,分析並揭示了轉子葉道內的馬蹄渦、通道渦、角渦、尾渦等復雜渦系及其與激波的相互干涉;特別是,分析並揭示了轉子葉道內頂隙射流的特點,得到了頂隙附近激波與泄漏流動的干涉形態及泄漏流動的發展,並著重給出了其與激波的干涉形態。Large eddy simulation of particle wake effect and rans simulation of turbulence modulation in gas - particle flows
顆粒尾渦增強湍流的大渦模擬以及氣固兩相流中湍流變動的數值模擬At first, the generating mechanisms of four kinds of wake features are studied in the thesis. we have simulated the features of ocean surface waves, kelvin wake, narrow v wake, turbulent wake, vortex wake, and internal wake. the kinetic equation of kelvin wake have been analyzed and improved, which can be used to calculate the kelvin wake of a submerged moving body
論文首先研究了四種常見尾跡特徵的產生機理,模擬得到了海面、 kelvin尾跡、窄v尾跡、湍流和渦流尾跡以及內波尾跡特徵;改進了kelvin尾跡的動力學模型,使之能夠計算運動物體下潛后的kelvin尾跡波高分佈。The results are compared with the cases in a single - layer fluid, showing that the density stratification can have a relative large effect on the drag and lift coefficients as well as the vortex shedding
計算受迫振蕩圓柱體的升力系數、阻力系數隨時間的演化曲線和圓柱體的尾渦分佈,以及圓柱體的受迫振蕩激發兩層流體內界面的擾動,並與均勻流體的情況進行了比較分析。Moreover, aircraft actually generate several vortices ? off the tail flaps, control surfaces and other areas of air - pressure discontinuity, states alan j
此外,連續體動力學公司的總裁畢拉寧說,飛機其實會產生好幾個渦流- -尾襟翼、操縱面與其他產生氣壓不連續的區域。Engineers are working on ways to detect hazardous wake vortices so pilots can avoid them or to design aircraft that leave safer skies behind them
工程師正在研究,想找出有效的點子,偵測危險的機尾渦流,或設計不會危及後方空域的安全飛機。The principal contributions of this dissertation are : 1. a high fidelity and real - time rotor wake inflow model was built up. based on peters - he finite states wake theory, a new influence coefficient matrix for high speed flight was derived, the modified wake model is better suitable for the flight state with a large wake skew angle
本模型以peters - he有限狀態尾跡理論為基礎,修正了大尾跡傾斜角時的誘導速度影響系數矩陣,並結合了王氏渦流理論,導出了旋翼誘導速度垂向分量和旋轉分量的表達式,可計算平尾、尾槳和垂尾氣動中心處誘導速度各分量。Continuum dynamics and boeing go further by introducing “ active forcing ” of the vortices to induce a wobble, or “ waviness, ” into the flow to hasten breakup even more, dissipating it in perhaps 1. 5 to two nautical miles
連續體動力學公司與波音公司則更進一步,以主動形成的渦流在機尾亂流中誘發晃動,或曰波動,使機尾亂流潰散的速度更快,也許只會綿延1 . 5 ~ 2海里(約2 . 8 ~ 3 . 7公里) 。分享友人