湍動邊界流動 的英文怎麼說
中文拼音 [dòngbiānjièliúdòng]
湍動邊界流動
英文
turbulent boundary flow- 湍 : [書面語]Ⅰ形容詞(湍急) rapid; rushing; torrential; swiftⅡ名詞(急流的水) rapids; rushing waters
- 邊 : 邊Ⅰ名詞1 (幾何圖形上夾成角的直線或圍成多邊形的線段) side; section 2 (邊緣) edge; margin; oute...
- 界 : 名詞1 (相交的地方; 劃分的界限) boundary 2 (一定的范圍) scope; extent 3 (按職業、工作或性別等...
- 流 : Ⅰ動1 (液體移動; 流動) flow 2 (移動不定) drift; move; wander 3 (流傳; 傳播) spread 4 (向壞...
- 邊界 : boundary; frontier; border; borderline; edge range line; periphery
- 流動 : 1. (液體或氣體移動) flow; run; circulate 2. (經常變換位置) going from place to place; on the move; mobile
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A one - dimensional oceanic mixed layer model with the m - y level - 2. 5 turbulence closure schemes is employed. the rate of energy loss by breaking waves is estimated by parameterization and incorporated into the model as a source of turbulence kinetic energy ( tke ) by modifying the existing surface boundary condition of tke equation. the velocity field and turbulence energy budget are calculated under different forcing conditions ( the results given below are for a wind speed of 20 m / s. )
採用一維2 . 5階湍封閉混合層模式,根據參數化方法對波浪破碎導致的能量耗散率進行了估計,通過改變湍動能方程的上邊界條件引入波浪破碎對湍動能生成的影響,計算了不同風應力強迫下的混合層流場結構和湍能量收支(下述給出的結果是取風速為20m s得到的) 。Using the system designed in this thesis work, flow field calibration of the wind tunnel is accomplished, which covers dynamic pressure drop coefficient, dynamic pressure time stability, axial static pressure gradient, boundary layer, and degree of turbulence, etc. boundary layer measuring principle and method are especially described in detail, the relationship between boundary layer thickness, wind speed setting, and the depth of the experimental section is summarized, and finally the calibration data for th e model center zone under specific wind speed are given
然後利用本文設計的系統完成了落差系數、動壓時間穩定姓、軸向靜壓梯度、邊界層及湍流度等內容的流場校測。特別對邊界層測量的原理及方法做了較詳盡的敘述,總結出邊界層厚度與設定風速、實驗段深度的關系,然後給出模型中心區一定風速下校正數值。Due to its complexity of the problem, the theories and experiment results obtained are discrepant, and some of them are even contrary one another. started from the influence by movement rules of small cavities and solid particles, the mechanisms of combined effect of cavitation and sand abrasion are study in this thesis from the aspect of the turbulent coherent structure near the wall. first, a dynamic equation is established for a single spherical bubble and single spherical sand under the non - turbulent coherent structure near the wall, and then a dynamic equation established under the turbulent coherent structure near the wall
首先從理論上推導出在典型湍流邊界層模式的非擬序結構下空泡與固體顆粒的近壁區運動方程,然後推導出湍流近壁擬序結構作用下的空泡與固體顆粒的近壁區運動方程,再將兩種不同條件下的的運動方程進行比較,指出湍流近壁區的擬序結構對空蝕與磨損的發生具有決定性的意義,即正是由於擬序猝發作用的存在,才使得空泡、沙粒對壁面的空蝕與磨損作用得以發生。As the moving particle in the turbulence boundary layer, the resistance on microbubble from water may be fallen inside the scope of the stokes law
作為湍流邊界層中運動的粒子,微氣泡受到水的阻力可能會在stokes阻力范圍內。To the cabin which is designed by the forth department chongqing communication college, the model which includes the air in the cabin, generator set and public muffler is built integer, meshed, and added by boundary condition and load. the normal k - model etc are used to be turbulence model of the air in cabin respectively, the turbulence model is calculated by simplef or simplen algorithm, and by the first order accurate msu or the second order accurate supg in advection discretization scheme
論文對艙內空氣、發電機組和公用消聲器進行了整體建模和網格劃分,施加機組艙模型的邊界條件和載荷,採用標準k -等多個模型來分別模擬機組艙通風散熱的空氣湍流流動,採用simplef和simplen兩種不同的數值演算法以及一階msu和二階supg的對流項分離方案來對流動模型進行運算。A separation in the boundary layer of fluid about a moving streamlined body, such as the wing of an airplane, causing a breakdown in the smooth flow of fluid and resulting in turbulence
氣流分離移動的流線型的軀體上流體邊界層上的分隔物,如飛機的機翼,在平滑的流體流動中會引起故障和湍流Based on prandtl ' s momentum transportation, this paper calculates in detail the physical quantities such as eddy viscosities, and ratio of eddy viscosity to motion viscosity, total stresses with respect to relative position in three regions of viscous sub - layer, buffer layer, and main turbulent stream for non - newtonian fluid flowing turbulently in ducts, which according to karman ' s three layer models and measurement of fluid parameters in evaluation apparatus, discusses the influence of polymer drag reduction on flowing properties of non - newton fluid, analyzes quantitatively principle of turbulent reduction phenomenon and condition of increasing reduction rate
摘要以普蘭德動量傳遞理論為基礎,按照卡門的三層模型,通過室內模擬環道用0號柴油及加入減阻劑在圓管內的流動參數的測定,計算了非牛頓型流體管內湍流邊界層的層流內層、過渡層、湍流中心的渦流粘度,渦流粘度與運動粘度比、總應力隨相對位置的變化等定量參數,探討了高分子減阻劑對非牛頓流體流動特性的影響,對湍流減阻現象的機理與增大減阻率的條件進行了定量分析。Artificial periodic disturbances are introduced to the outer field of turbulent boundary layer in an closed - circuit open water channel. statistical method is employed for analyzing the velocity - fluctuation - time - series. the effect of the disturbance to turbulent structure in boundary layer is studied
在開口式循環水槽底部湍流邊界層外區中引入周期性擾動,對湍流場的速度脈動時間序列信號進行了統計分析,研究了湍流邊界層中周期性人工擾動對湍流結構的影響,結果表明高頻擾動的湍流中she - leveque簡稱sl湍流層次相似律成立。Turbulence over flat wall is presented with the cfd software cfd ace ( u ) when given by various inlet boundary conditions, subgrid model and turbulence intensity under the two - dimensional circumstance. on comparing these outcomes with the experimental data, we can analyze the impacts that all these factors have on the development of flow boundary layer
採用計算流體力學軟體cfdace ( u ) ,在二維情況下應用不同的進口邊界條件、亞格子模型和來流湍流度對平壁流動進行大渦模擬,並將模擬結果與已有的實驗結果進行對比,分析比較了這些因素對流動邊界層發展的影響。The direct numerical simulation methods for turbulent spots in the channel, open - channel and boundary layer flows are built respectively. effective algorithms composed of time - advancing, over - relax iteration and multiple grid methods are planned to raise computational efficiency
分別建立了適用於在槽道、明渠和平板邊界層流動中直接模擬湍斑的數值方法,並精心設計了時間推進、超鬆弛迭代和多重網格等高效演算法,以提高計算效率。Refined grids were utilized in a large - eddy simulation model for obtaining high - resolution planetary boundary data and analyzing surface layer turbulence. simulation results showed that refined meshes reduced turbulent contributions of subgrid scales, sensitivity of simulation results to sgs parameters decreased, and features of the whole boundary layer were explicitly resolved better. results also revealed flux - profile relationship correctly in surface layer and a good agreement of turbulent velocity characters with observation. therefore, it concluded that the les method was able for simulation of surface layer flow and turbulence, and might be used for further applications
採用加密網格的大渦模式獲取邊界層風溫場的高解析度模擬結果,並據以分析近地面層大氣的湍流特性。結果表明,較小的網格尺度使次網格湍流貢獻率大為降低,模式計算結果對次網格參數的依賴性減小,邊界層整體特徵得到更好的反映。同時,模擬出的近地面層通量廓線關系及湍流速度特徵與實際觀測結果吻合甚好,表明模式具有反映近地面層平均運動和湍流特性的能力。The decaying of periodic disturbance in turbulent boundary layer along wall - normal direction
周期性擾動在湍流邊界層中沿法向的衰減All of the results indicated the turbulent boundary layer had been turned into the laminar layer. the skin friction coefficient drops rapidly. this result not only proved the phenomenon of reverse transition had occurred, but also showed that this condition was drag - reducing condition
實驗結果表明板面附近的流動已由湍流流動轉變為層流流動,同時平板表面的摩擦系數較沒有溫度梯度時有大幅度下降,不僅證明了邊界層逆轉捩現象的存在,也說明了這種條件起到了減阻的效果。The micro boundary layer experiment is carried out from 8mm to 14mm of a 15mm - long micro plane. re numbers vary from 35, 000 to 150, 000 and 4 different mach numbers are selected. some new characters are discovered, such as velocity curve factor is smaller than that of well developed normal scale turbulence boundary layer
微尺度平板邊界層實驗選取從總長度為15mm的微平板前緣8mm到14mm之間的7個站位, 4種馬赫數, 13個不同雷諾數(從35000到150000 )的實驗狀態,發現了該尺度下邊界層流動的一些新的特點,如形狀因子比常規大尺寸下充分發展湍流狀態的形狀因子更小等。Because there are obviously multi - dimensional feature at the cleaning valve, we adopt the three - dimensional viscous flow field and the spalart - allmaras model to calculate the flow coefficient, to raise the solution of setting the boundary condition, to study the flow properties and corresponding parameter varying
清洗液閥門具有明顯的多維流動特性,用三維流場計算其流量系數,採用spalart - allmaras湍流模型(簡稱s - a模型) ,提出了邊界條件的設定方法,來研究清洗液閥門的流量特性以及相應的參數變化規律。The method of generating elements and nodes automatically by reading coordinate data on surface of bus body is introduced and realized to discrete the topology space of three - dimensional turbulent flow field around buses
客車周圍流場三維湍流數值模擬的空間離散化研究實現了由車身外表面離散點坐標數據文件自動剖分生成單元、節點和邊界條件的方法。The fourth - order explicit upwind - biased compact difference schemes are used in the spatial discretization of the nonlinear convection terms. these difference schemes can be used in all computational region including the boundary neighborhood, and can overcome the difficulty not adapting simultaneously in the boundary neighborhood for general three - dimensional fourth - order central difference schemes, and improve computational stability a nd resolution. the compact difference equations with high accuracy and resolution for solving the incompressible n - s equations and perturbation equations are composed of these compact difference schemes, and provides an effective numerical method for the investigations of the turbulent spots and coherent structures
文中發展了四階時間分裂法用於navier - stokes方程及其擾動方程的時間離散;對分裂得出的關于壓力的poisson方程和關于速度的helmholtz方程,建立三維耦合四階緊致迎風差分格式;這些格式適用於包括鄰近邊界點在內的計算區域,克服了三維各自用四階中心差分格式離散不適用於邊界鄰域的困難,並提高了穩定性和解析度,用這些格式分別組成了數值求解navier - stokes方程及其擾動方程的高精度、高解析度的緊致差分方程組,為湍斑及湍流相干結構的研究提供了有效的數值方法。The effect of periodic disturbance to the hierarchical structure in turbulent boundary layer
周期性擾動對湍流邊界層層次結構的影響The numerical models with the wall impulse as initial perturbation of turbulent spots were proposed. the above compact difference systems are used in the several typical flows, such as. the channel, open - channel and boundary layer flows the various complicated boundary conditions satisfying n - s equations are carefully conducted
建立了以壁面脈沖為初始擾動的湍斑數學模型,並將導出的navier - stokes方程的緊致差分方程組應用於槽道、明渠和平板邊界層等典型流動,提出了嚴格滿足navier - stokes方程的邊界條件。The results show that rsm can accurately simulate the movement of the turbulent buoyant flow in reservoir and the anisotropic turbulence due to the thermal stratification. however, rsm is difficult in convergence, bad stability and more time consuming. rsm is suitable when the high accuracy is concerned and geometry boundary is simple
結果顯示, rsm模型能精確模擬水庫中湍浮力流運動規律和由於溫度分層引起的紊動量的各向異性的特徵,但其收斂性、穩定性及經濟性較差,適用於計算精度要求較高且流域邊界較為簡單的流動。分享友人