In this paper, a three-dimensional multi-level hydrodynamic model with curvature correction in curvilinear coordinates has been developed based on the update turbulent theory and numerical method, which can effectively solve the practical problems of flows and water quality transportations in hydraulic engineering, and can strengthen the practical usage of the mathematical model.

本文基于現(xiàn)代紊流理論欧美黄色小视频免费观看、現(xiàn)代數(shù)值計算方法建立適合描述水利工程中紊流規(guī)律的非線性數(shù)值模型午夜人人操，即曲線坐標(biāo)系下的多層紊流水動力模型，旨在提高紊流精細(xì)模擬的實用性丰满熟妇口爆吞精，以求有效地解決水利工程中的水流和輸運現(xiàn)象的實際問題谁有免费的黄色视频。

Main creative points of the thesis are as following:1. It is the first time to apply 2-D and 3-D turbulent model of the air-water two phases flow to the study on hydraulic properties of groyne. It makes description of the turbulent flow field to be possible precisely. This offers a more accurate method to determine the water surface in channel improvement.2. Based on the results of experiment and simulation for 3-D turbulent model of air-water two phases flow, a new formula to compute the height of damming is built.3. Based on the 2-D mode and the formula to compute the height of damming, the subdivision method of 2-D computation for water surface at upstream and downstream.

本文的創(chuàng)新工作主要是：首次將三維水氣兩相流紊流數(shù)學(xué)模型應(yīng)用于丁壩水動力學(xué)特性研究，使丁壩附近流場和紊動場的精細(xì)描述成為可能www.久久思思热.com，為航道整治中水面線確定提供了一個更為準(zhǔn)確的方法国产一级在线观看免费视频；(2)基于水槽實驗和三維水氣兩相流紊流數(shù)學(xué)模型數(shù)值模擬結(jié)果，建立了新的丁壩前奎水高度計算公式黄片大全免费看的mm视频；(3)基于上述奎水高度計算公式和本文二維水面計算數(shù)學(xué)模型95视频网址，首次提出了丁壩上下游二維水面分段計算方法。

In this thesis, study is on the basis of N-S equation and standard turbulent flow mould. Numerical simulation is given to turbulent flow inside impeller of LB50-160 type centrifugal pump.

本文基于N-S方程和標(biāo)準(zhǔn)k-ε紊流模型www。五月天。com，對LB50-160型離心泵設(shè)計流量下葉輪內(nèi)流場三維紊流進(jìn)行了數(shù)值計算欧美亚洲日韩一级特黄在线，獲得了葉輪內(nèi)流場的速度、壓力分布全网最新黄色网站，捕捉到了一些重要的流動現(xiàn)象黄色视频免费在线观看不卡。

Numerical simulation to three-dimensional turbulent flow in multistage axial compressor blade row is carried out, where high resolution third-order ENN scheme is adopted to catch the shockwave and simulate the turbulent flow correctly, and LU-SGS implicit method is chosen to improve computation rate. A nicety and high efficiency numerical simulating system is thus constructed.

對多級軸流壓氣機葉柵內(nèi)三維紊流流場進(jìn)行數(shù)值模擬，采用高精度高分辨率的三階ENN格式以保證對激波的捕捉和對紊流特征的正確模擬久久久极品精品，利用LU-SGS隱式解法提高了計算速度久久久精品国产自在看，從而構(gòu)成了一種既準(zhǔn)確又高效的多級跨聲速軸流壓氣機紊流流動數(shù)值求解系統(tǒng)。

Considering the characters of the viscoidal turbulent flow over high-speed train,the computing model of the outer fiow field for high-speed train has beenestablished based on the incompressible fluid Navier-StOkes epuation and theturbulent model of ke two equations. The equation set of the flow field problemvia finite element methods has been set up.

根據(jù)高速列車粘性紊態(tài)繞流的特點偷拍自慰，在較少簡化的條件下以Navier-Stokes方程和κ-ε兩方程紊流模型為基礎(chǔ)高清无码不卡网站，建立了高速列車外流場的計算模型，在近壁區(qū)域采用壁面函數(shù)修正紊流模型日韩黄色片网站。

The results of this study indicate that changing the angle of the intake port has a profound effect on the flow field during the intake stroke of the engine cycle. For the case with the intake-exhaust valves canted at zero degree (the so-called vertical valves), the tumble ratio, swirl ratio, turbulent intensity, and turbulent kinetic energy in the direction perpendicular to the bisecting plane of the cylinder are at their highest levels than those obtained for the other cases. This effect is most pronounced after the compression stroke of the cycle. As a result of this study, it is observed that the behavior of the overall flow field from the intake to the completion of compression stroke has a major impact on the effectiveness of the mixing of fuel-air prior to the ignition of the engine cycle.

結(jié)果顯示国产青草视频免观看视，改變進(jìn)排氣閥的傾斜角度對進(jìn)氣期間的流場變化有很明顯的影響黄色视频一级片免费，其中以垂直閥(進(jìn)排氣閥傾斜0度)所得的 Y軸向(Y方向系垂直於將汽缸對分為二平面的方向)滾流強度、渦漩比ⅰgao23、紊流強度欧美黃色网络、紊流動能等流場強度為最強；若以流體經(jīng)活塞壓縮后的流場特性進(jìn)行探討性愛小说视频，所得結(jié)果顯示壓縮沖程對汽缸內(nèi)流場的效應(yīng)是不容忽視的欧洲aaaa片；因此由進(jìn)氣到壓縮過程結(jié)束的整體流場現(xiàn)象，才是影響引擎點火前的油氣混合程度與燃燒品質(zhì)的關(guān)鍵自拍偷拍一区12。

In our research, a 3-D numerical simulation calculation of the outside flow field of the flat-headed van-body truck has been made first. A RNG k-? turbulence model which can increase the calculation precision of the separation flow has been adopted, and the results show that the calculation of the van-body truck with the RNG k-e turbulence model is more exact than that of the standard k-e turbulence model.

本研究首次對平頭廂式貨車外部流場進(jìn)行了三維數(shù)值模擬計算国产在线97色永久免费视频，模擬采用可以提高分離流計算精度的RNG k-ε紊流模型，計算結(jié)果表明其計算精度較標(biāo)準(zhǔn)k-ε紊流模型有顯著的提高欧美另类呦交视频免费观看。

PDA(particle dynamics analyzer system) was used to measure the flow velocity of particles in the XFD-12 flotation cell, the results show that tangential mean velocity in the radial direction changes from positive to negative in the flotation cell, naught point emerge in the medium of the radial direction ,it is where backward fluid emerge ,shear stress of backward fluid induce the particle detachment from bubbles .

汁算數(shù)據(jù)與實際礦石篩析結(jié)果都表明欧美另类视频第一页，紊流強度增大，泡沫中粗粒級含量減小40岁四川熟女高潮片。 4黄色网站免费能看的网站。用PDA在XFD-12型8L浮選機中測定的速度值，進(jìn)行混合區(qū)国产污视频网站免费在线观看、分離區(qū)、泡沫區(qū)紊流運動功率譜計算色x色色视频，得紊流脈動頻率国产三极片在线观看，混合區(qū)小于20Hz，分離區(qū)在20-30Hz之間爱干免费视频，泡沫區(qū)在25-35Hz之間欧美黄色视频看看，浮選槽內(nèi)紊流脈動以低頻為主，且紊流脈動動能是混合區(qū)大于分離區(qū)大于泡沫區(qū)超碰在线播放观看。

An advanced combined turbulent lubrication model is proposed: low turbulence Reynolds number k-e model is used to describe the flow in the near-wall regions, and algebraic Reynolds stress model is used to describe the flow in the turbulence kernel, with flow continuity kept between the two models and transition criterion set to fit Leutheusser's measurements.

提出了先進(jìn)的復(fù)合型紊流潤滑理論：以低紊流雷諾數(shù)k-e模式描述近壁區(qū)內(nèi)的流場黄色网站在线看a，而以代數(shù)雷諾應(yīng)力模式描述紊流核心區(qū)內(nèi)的流場，二區(qū)間流場連續(xù)過渡被干爽死黄色视频，并依據(jù)Leutheusser實驗結(jié)果設(shè)定過渡準(zhǔn)則欧美国产欧美日韩。

The previous researches have been done experiments mostly in the Water tank. In order to simulate turbulence of flow in river and research its characteristics, the characteristics of turbulence are studied by experiments in the water channel with ADV technique. The research results indicate that R.M.S. velocity linearly relates to the oscillating-grid frequency; R.M.S. velocity decays by power exponent relates to the distance from the grid midplane; and the relationship between the geometrical factors and the free movement space of water is direct proportion.

以往研究大都在水箱中對振動格柵紊流特性進(jìn)行實驗研究，為能模擬天然河道中的紊流未满十八岁禁看的色色视频，研究天然河道中紊流特性1024在线视频一区二区，利用ADV技術(shù)在水槽中對振動格柵紊流進(jìn)行了實驗研究研究結(jié)果表明：均方根速度與格柵振動頻率成線性關(guān)系；均方根速度與距格柵中平面的距離成冪指數(shù)關(guān)系衰減黄色视频手机在线视频；幾何系數(shù)與水的自由運動空間成正比關(guān)系干妞毛片。