drag velocity 中文意思是什麼
drag velocity
解釋
摩阻流速-
Firstly, based on the present research all over the world, a 3d quasi - single phase model is built together with k - equations. the special feature of this model is taking account of the influence of interaction between liquid and gas, that is to say, the influence of interphase drag force, lifting force perpendicular to the relative velocity, virtual mass force and gas or liquid volume fraction in the fluid field have been considered. a 3d two - fluid model is also built in order to describe more accurately the fluid flow on distillation trays by comparing the computational results of quasi - single phase mathematical model with of two - fluid mathematical model
本文在國內外已有的研究基礎上，首先建立了以k - （封閉模型為基礎的三維擬單相流模型，該模型的特點在於充分考慮了氣液兩相間相互作用的影響，即計入了相間曳力、橫向升力、虛擬質量力和氣、液相含率對流場的影響；並建立了塔板三維雙流體模型，主要目的是通過對比擬單相流數學模型、雙流體數學模型的計算結果，建立能夠準確描述塔板上流體流動的數學模型。 -
Based on theoretical analysis, microbubble drag reduction is due to structure change of turbulent boundary layer caused by the microbubbles. experiments testify microbubble drag reduction for turbulent boundary layer, as well as bubble size, main flow velocity, etc. affecting the reduction ; with proper flow field model, turbulent model and difference scheme, numerical methods simulate the effect of boundary layer and bubble numbers on dray reduction
理論分析提出微氣泡降阻機理在於其引起湍流邊界層結構的變化；實驗證明了微氣泡對湍流邊界層的降阻作用以及氣泡尺度、主流速度等對降阻作用的影響；數值方法利用適當的流場模型、湍流模型和差分格式，模擬邊界層和氣泡數等對降阻的影響。 -
The 6. 8 mm remington spc is limited to relatively short bullets to fit within the maximum cartridge length of 5. 56 mm weapons, so the grendel has a shorter ( 39 mm ) and fatter case, leaving room for longer, low - drag bullets, which retain their velocity out to long ranges
8毫米的雷明頓spc缺少相配套的短彈頭使之合適於5 . 56毫米武器的最大彈藥筒尺寸，因此格倫德爾的彈殼更短（ 39毫米）更胖一點，為遠距離低阻彈頭留出空間。 -
The frontal cross - sectional area, the velocity of the swimmer, the wetted surface area of the swimmer, the density of the fluid, and the coefficient of drag will all be the same whether the body is on the front or side
身體前部分的橫截面面積，運動員的速度，運動員的觸水面積，液體的密度以及拖曳系數都是一樣的而無論身體是朝向一邊或前傾。 -
The 3d turbulent flow fields around high - speed trains of four kinds of model uain have been calculated by 3d parallel compute program coded with the algorithms presented in this thesis. from the calculation results, the aerodynamic drag of different types of model trains are obtained, some characteristics of the flow field over the high - speed train are analyzed preliminarily such as pressure distribution and diversification, velocity distribution and diversification, and the affections of different train head shape to pressure. velocity, pressure gradient and the like
用三維并行計算程序模擬了四種不同高速列車車型的外流場，獲得了不同車型的運行阻力；詳細分析了列車附近流場的壓力分佈及其變化情況，討論了列車頭型對列車通過時產生的壓力波動的影響；分析了四種車型外部流場的速度分佈規律及其變化情況，分析了列車頭部形狀對它們的影響。 -
The drag reduction of riblet biomimetic non - smooth surface is given out by numerical simulation with cfx. through analysis of velocity vector field and velocity fluctuation this article probe into drag reduction mechanism of unsmooth surface. through analysis of behavior of single microbubble and turbulent kinetic energy this article indicate drag reduction mechanism of microbuble
對仿生非光滑表面減阻機理，採用流體力學分析軟體cfx進行了數值模擬，通過對速度場、剪切應力、渦量的計算結果進行分析，得出了仿生非光滑表面減阻幾種主要原因。 -
In an edt, the electrical power produced is the rate of work done by the magnetic drag ? that is, the magnitude of the drag force times the velocity of the satellite ( relative to the magnetized ionosphere ), which is about 7. 5 kilometers per second in leo
在edt中，生成的電功率等於磁拖曳力做功的速率，也就是拖曳力的大小乘上衛星相對于磁化電離層的速度，在leo上約為每秒7 . 5公里。 -
It is found that drag reduction occurs with adequate wavenumbers and grows with an increase of h. the mechanisms are revealed through variations of velocity profile and the decrease of wall shear stress
分析減阻機理是流速分佈曲線及近壁區速度梯度介於層流與湍流之間， h值增大引起壁面剪應力顯著下降。 -
The flowfield over low - drag and long - range projectile with small attack angle is numerically studied from transonic to supersonic velocity. it provides basic work for aerodynamics characteristic of this projectile and for lateral jet interaction flowfield, and it shows this projectile can decrease drag. zonal method is tried to compute flow over projectiles and results is satisfied, but computation is much slower
系統研究了低阻遠程彈丸在小攻角狀態，低跨聲速、高跨聲速和超聲速時的非對稱繞流流場，為該彈形氣動力研究提供理論指導並為彈丸側噴流研究奠定基礎，結果顯示低阻遠程彈丸外形具有優化繞流場、減小空氣阻力的特點。 -
Moreover, this paper investigates the influences of surfactant aqueous solutions on flow characteristics of a mmc. sodium dodecyl sulphate aqueous solution and alkyl polyglycoside aqueous solution are used as working fluids. the experiment results indicate that the drag reduction depends on flow velocity and temperature ; the drag reduction effects aren ’ t very obvious in laminar flow region, but when fluid enter turbulent flow region, the drag reduction increase notably, the drag reduction effects
研究結果表明，阻力減小率（ dragreduction ， dr ）與流速和溫度有關;層流區內表面活性劑的減阻效果不是特別明顯，但進入紊流區后減阻效果開始增強，尤其進入旺盛的紊流區后減阻效果大大增強;溫度提升也可增加dr ，但在溫度較高時添加sds后減阻效果的改善卻不及apg 。
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