渦尾跡 的英文怎麼說
中文拼音 [guōwěijī]
渦尾跡
英文
vortex trail-
In chapter 2, a simplified analytical model is presented for the analysis of the bvi mechanism, adopting the beddoes " prescribed wake model. by this model, the azimuthal location and miss - distance of the bvi and the radiation directivity of the bvi noise are calculated and discussed, and some conclusions are obtained
在第二章,使用beddoes預定尾跡模型,建立了一個用於旋翼槳-渦干擾特性機理分析的簡化數學模型,分別對旋翼槳-渦干擾位置、槳-渦干擾距離和聲輻射方向性等進行了計算和分析,得出了有意義的結果。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。The results indicated that the generation of trailing - vortex of downstream adjacent vanes could be restrained effectively by upstream wake when the passing frequency and the amplitude of wake defect satisfy some conditions, associated with a significant enhancement of time - averaged aerodynamic performances : loss coefficient reducing 40. 2 % and the ratio of loading coefficient and loss coefficient increasing 93 %
研究表明:滿足一定通過頻率和虧損幅值條件的尾跡能夠有效抑制下游相鄰葉排尾緣渦的生成,達到控制或是推遲附面層非定常分離的目的,從而使得流場時均性能大幅度的提高,損失系數降低了40 . 2 % ,功損比增加93 % 。Numerical simulation of unsteady vortex in the wake of cascade flow
葉柵流場尾跡中非定常渦系的數值模擬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 。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。In the pseudo - time region, high efficient lu - sgs scheme was used in time - marching. cases with uniform or non - uniform inlet stagnation pressure and with or without tip - gap flow were studied. computed results showed that complex structure vortex appeared and secondary flow occurred in the flow of cascade with tip - gap
對進口總壓均勻或總壓周向虧損(模擬上游尾跡) 、葉尖無間隙或有間隙等三種不同情況的流場計算結果,進行對比分析發現,流場中廣泛存在流動分離、分離渦以及二次流,這是引發非定常擾動的根源。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。Furthermore, the horseshoe shape vortex system occurred to the upstream of the jet exit and the layer structure of vortexes occurred to the wake of the reverse flow region downstream of the jet are also investigated
另外,觀測到射流噴口上流的馬蹄渦系以及射流逆流區下游尾跡區旋渦的層狀結構形式。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 spanwise characteristic length determines the transition features and global properties of the wake. especially for the specific spanwise characteristic length linear stable mode can dominate the wake in place of mode a and determine the spanwise phase difference of the primary vortices shedding
尤其值得注意的是發現在特定的展向特徵長度下線性穩定的展向模態會取代模式a而在尾跡中占優並決定卡門渦脫落的展向相位差。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。By using the method of construct boundary condition at the entrance, it did a research on the formation principle of karman vortex and believed that there was no direct relationship between the formation and the object itself. the existence of the object just provided a basic current in the space to generate a absolutely unstable district and so the explanation of absolutely unstable model near wake flow is more suitable
通過採用構造入口邊界條件的方法,對k rm n渦街的形成機理進行研究,認為渦街的生成與物體本身無直接關系,物體的存在只是在空間內提供了可以產生絕對不穩定區域的基本流,因而近尾跡絕對不穩定模式的解釋較為合適。The relationship between the non - dimensional drag coefficient of sma plate face and time is presented, and the pressure distribution on and around the sma plate surface as well as the karman vortex configuration in the wake at a certain time are given
給出了形狀記憶合金薄板表面的流體無量綱阻力系數隨時間的變化關系,同時給出了某一時刻薄板表面及其周邊的壓力分佈和薄板尾跡中的卡門渦街形態。分享友人