脈動場 的英文怎麼說
中文拼音 [màidòngchǎng]
脈動場
英文
pulsating field-
One cardiac cycle is divided into 50 parts in the transient analysis to accurately simulate the continuous pulsatile blood flow in the coronary artery, the hemodynamic parameters of the atherosclerotic and the controlled models at each of the 50 moments were computed in accordance with the physiological condition
這些計算包括:脈動流情況下的非狹窄和狹窄不對稱性對狹窄流場的影響,分岔角度變化時動脈狹窄和非狹窄的各種血流動力學參數的計算模擬。By performing fourier transformation, the relationship between the turbulent intensity of the particle and that of the carrier fluid was obtained which makes clear that particle size, specific gravity, velocity gradient, and the characteristic frequency of energy - containing eddies are four basic influencing parameters. it is proven theoretically that under certain conditions, the stream - wise and transverse particle turbulent intensities exceed those of the carrier fluid. based on the equations of two - phase flow, the presence of fine sediment suspension is shown to attenuate the turbulent intensity of the water
通過對細小顆粒在剪切流場中運動方程的fourier分析,得到了顆粒脈動強度和流體脈動強度之間的定量關系,表明顆粒粒徑、顆粒密度、流速梯度以及紊動場含能旋渦的特徵頻率是影響顆粒脈動強度的主要因素,首次從理論上證明了在一定條件下,顆粒在縱、垂向的脈動強度均會超過相應的流體脈動強度,為已有的實測資料提供了合理的解釋。In this work, a new dual triangulate bluff body vortex flowmeter was developed, the flux lower limit value of which lower by 50 % that of the old single bluff body vortex flowmeter. the linear correlation of the correlation between the velocity pressures of fluid disturbs wave and that of vortex precession in vortex precession flowmeter was brought to light, and a spectrum phase discrimination method based on fft to remove the effect of fluid pulsating interference on vortex precession flowmeter was advanced
研製出比傳統單鈍體渦街流量計流量下限降低約50的新型雙鈍體渦街流量計;揭示出脈動流中旋進旋渦流量計流體振動特性,並在此基礎上提出基於fft相位判別的數字信號處理方法來消除流場脈動對旋進旋渦流量計的干擾的方法。3. a three - dimensional - acoustic doppler velocimeter has been used to measure the velocity and turbulence in a compound channel with vegetated and unvegetated flood - plains. particulary in the interface region between main channel and floodplain. the distribution in three coordinate directions of velocity and turbulence intensities and the renolds stresses are presented. the momentum transfer at the main channel flood - plain interface can be described as an apparent shear stress which can be quantified as a function of the local turbulence at the interface
採用adv對灘地種樹前後灘槽交界區域的流速場進行了量測。分析了灘槽交界區域的垂線流速、紊動強度和雷諾應力的變化。將灘槽交界的動量傳遞描述為一表觀應力,這個表觀應力可以看作是交界面處的脈動函數並將其定量化。With the research in the paper succeeded it would be certain that the helical gear pump would replace the spur gear pump now widely existed in the market and also could replace the other type of hydraulic pump in some areas, which surely greatly decrease the cost of manufacture and advance the development of technology. the importance is undisputable
本論文研究的斜齒嚙合式低脈動齒輪泵可代替現廣泛存於市場上的直齒輪泵,並能在很大程度和范圍內替代其它形式液壓泵的作用,這對于促進機械裝備的技術進步、降低機械裝備的製造成本具有十分重要的意義,其應用前景將十分廣闊。Code for field measurement of vibrations and pulsations in hydraulic machines
水力機械振動和脈動現場測試規程In chapter 3, the subgrid eddy - viscosity model for large eddy simulation is applied to calculate the three dimensions unsteady periodic turbulent flow in yantan francis turbine. the pulsating characteristics of some main physical parameters in flow field are found. the calculated axial water thrust of hydraulic turbine agrees with the model - test value
第三章採用大渦模擬亞格子渦粘模型,對巖灘混流式水輪機的流場進行三維非定常湍流分析,得到了流場中各物理量的脈動特性,計算出ms的軸向水推力與模型試驗值大小相當;同時論證了對于下機架承重的混流式水輪發電機組可採用其推力軸承負荷作為水電站廠房振動的最大垂直激振荷載。In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal, wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station, in which the signal is decomposed into different frequency band, and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基於李家峽水電站雙排機組振動的現場試驗研究,並且針對傳統頻譜分析方法傅立葉變換( fft )對于非平穩信號已力不從心這一缺陷,利用小波分析方法在時域和頻域上同時具有良好的局部化性質,通過對開停機這一典型非平穩過程信號進行小波及小波包分析,將其分解到不同頻帶內,獲取微弱信息和提取優勢頻率,並對其作振源分析,得出開停機初始時刻因水流不穩均出現強烈的振動現象,且低頻段信號能量最大,開停機過程水流脈動壓力和尾水渦帶擺動是引起定子基礎振動的主要原因。Because the controller is easy to get the position of rotor by the encoder, we can continuously rotate the flux of the armature rotor by applying spwm method to the control system. the continuous rotation of the flux of armature make the output torque of motor has no ripple
由於通過編碼盤可以輕易獲得精確的電機轉子位置信號,故運用spwm調制方法可以使得無刷機的電樞磁場按照圓形軌道連續旋轉,從而實現輸出轉距無脈動。A wavelet method for the simulation of a stochastic wind field
利用小波逆變換模擬隨機風場的脈動風The research result demonstrates that along with the increment of reynolds number, the root mean square value of outer fluctuating magnitude of the external diameter in fall frequency band increases, the root mean square value of fluctuating magnitude of the external diameter in high frequency band decreses, demonstrating that the fluctuation of flexible pipe wall changes fluctuation don field of original rigid pipe, large - size eddy motion increases and small - size eddy motion decreases, this reduces energy loss and increases friction reduction effectiveness
研究結果表明:隨著雷諾數的增加,全頻帶的外徑脈動的均方根值加大,但高頻帶外徑脈動的均方根值減小,說明柔性管管壁脈動確實改變了原剛性管的脈動流場,大尺度渦的運動加劇,低尺度渦運動減弱,從而使得能量損失減少,減阻效果增大。A new method for realization of multi - channel data acquisition on windows flat form is brought forward in allusion to the feature of hyper - low frequency with water pressure pulsation in hydroelectric sets. and various anti - disturbance solutions are adopted in connection with the detection environment. the device proved to be able to has been meet predetermined requirement by its engineering application
針對水力發電機組水壓脈動超低頻特性,開發出一種在windows平臺上實時多通道數據採集系統,並結合測試現場環境,提出了抗干擾的各種措施.經實際運用,達到了預定要求Through research of automatic dosing system, established by determining automatic dosage in the methods of transmittance pulsation, streaming potential and mathematical model, it can be concluded that the automatic dosing system brought forward in this paper can fulfill requirements of the technics. likely, this system can also be applied for dosing of other chemicals in water plants, chemical dosing of wastewater treatment plants and other similar places
通過對採用透光率脈動、流動電位、數學模型等方法確定混凝劑投加量建立的自動配投系統的研究表明本文提出的自動配投系統能滿足工藝的要求:同樣該系統也適用於給水處理廠其他藥劑的投加,適用於污水處理廠及其他類似場合藥劑的投加。Based measured aerodynamic parameter and simulated wind speed field, time - domain expression of static wind load, buffeting load and self - excited load for bridge and vehicle are introduced
基於測試的氣動參數和模擬的脈動風速場,給出了車輛和橋梁靜風力、抖振力及自激力的時域表達式。Gca silicon commutate battery charger are the ideal portable tools for charging, they are composed with the conditions of voltage dropping through rectifier transformer, then the bridge rectifying of rectification circuit. the output full - wave pulstin current charge the storage battery. the voltage changing composed with multiband switch. the outputcurrent can be adjusted. this kind of product used any moment onctarging anyplace
Gca系列整流充電機是由整流變壓器的降壓,再經過流電路的橋式整流,輸出全波脈動直流對電瓶進行充電,電壓調速同多頭波段開關組,輸出流可以調節,該產品用任何需要補充充電的場所。At present, mechanical impulse stepless speed regulators are applied extensively. because the structures of those regulators existing at present have a lot of advantages and disadvantages, it affects their application in the cases that small impulse output and stability are required
機械式脈動無級變速器是目前應用較廣泛的一種無級變速器,現有的各種形式的脈動無級變速器有一系列的優點,但也存在一些不足,影響了該無級變速器在一些要求輸出脈動值小、傳動連續平穩的工作場合的應用。Presently most of the theoretical method to predict the propeller - induced hull pressure fluctuation is based on the calculation method in which the pressure is induced by pulsating source in infinite flow. the calculation method is adopted and the corresponded computer program is complied. the propeller - induced hull pressure fluctuation due to blade thickness, blade load, cavity thickness and the change of the cavity volume can be analyzed respectively in the computer program
目前,螺旋槳誘導的船體表面脈動壓力的理論預報方法,大多是以無限流場中點脈動源誘導的周圍流場的脈動壓力的計算方法為基礎的,本文採用該方法編制了計算程序,可以分別考慮槳葉厚度、槳葉負荷、槳葉上空泡厚度及其體積變化在船體表面指定位置上產生的脈動壓力。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。According to the properties of both the structural style and the vibration mode of long cable - stayed bridge, and considering the correlation characteristics of natural wind, a practical method is introduced to simplify stochastic wind velocity field of long cable - stayed bridges for taking pylon wind field effect into account
為考慮斜拉橋橋塔風效應,根據大跨度斜拉橋結構形式特點,結合脈動風的相關特性,提出了一種簡化的大跨度斜拉橋三維脈動風場模擬方法。Pulsed field magnetometry
脈動場地磁測量分享友人