推力常數 的英文怎麼說
中文拼音 [tuīlìchángshǔ]
推力常數
英文
thrust constant-
A 3 - d viscosity turbulence model is used to analyze the unsteady around flow field of the thrust - vectoring engine of the jet vane, and results of the area including vane base, vane flake and motor shell are presented
摘要以推力矢量發動機的燃氣舵為研究對象,採用三維、粘性、湍流流動模型和數值分析的接觸網格技術,在定常流動計算的基礎上,對包含舵基、舵片和發動機殼體的區域進行詳細數值分析。In recent years, plentiful and substantial fruits achieved by the lb method in simulations of hydraulics, multiphase flows, flows in porous media and heat transfer as well as magnetohydrodynamics, have revealed a broad perspective of application of this method, it will become a powerful competitor to the conventional approaches. in order to absorb the recent achievement in theory and application of the lb method, explore new ways in hydraulic computation to promote the development of practice, some work is car ried out in this thesis, as following : advances in the theory research and application, deductive process of the d2q9 model and some other commonly used models of the lb method are summarized. based on the hydrodynamic and general boundary conditions, a new joint boundary condition is presented, it integrates advantage of the two conditions above and obtains very good results in dealing with all kinds of boundaries of flow fields
為了消化和吸收近年來lb方法在理論和應用方面的新成果,探索在水力計算方面的新途徑以促進lb方法實用化的發展,本文進行了下列研究工作:綜述了lb方法在理論研究和實際應用方面的新進展,以及d2q9模型的推導過程和其他一些常用的模型;在水動力邊界條件和通用邊界條件的基礎上提出了一種新的聯合邊界條件方法,它綜合了上述兩種邊界條件的優點,在流場的各種邊界處理中取得了非常好的效果,經過模塊化的處理以後這種邊界條件具有更好的實用性;針對均勻網格的lb方法計算效率較低的不足,提出了雙重網格的latticeboltzmann方法,通過二維poiseulle流動、后臺階流動和渠道方槽流動三個算例的模擬,證明這種方法能夠明顯地提高流場模擬的計算效率;此外,根據復雜區域流場的特徵提出了latticeboltzmann方法的分塊-耦合演算法,利用lb方法的計算特性實現塊與塊之間的數據交換,充分利用計算資源提高計算效率,通過對「 t 」型、 「十」型和「 x 」型分岔管道流場的模擬,展示了這種演算法的特徵和優點,以及它所具有的應用前景。Such highbrow outfits tend to have small, select clienteles and are constantly trying to broaden their appeal, often by offering discounts and staying open late on friday and saturday nights
那些陽春白雪類的機構傾向于擁有那些數量少的,精選出來的客戶,並且通常是通過提供折扣和周五周六晚上推遲打烊,設法持續擴大他們的吸引力。Through the analysis we found that the effect will become more obviously with the increase of thickness or width of superstratum and the decrease of the coefficient of foundation bed ; ( 3 ) anisotropy and nonlinear elastic f. e. m. model has been established and the effect of stress dispersion in compound two - layer foundation was analyzed on the base of the model. from the analysis we can conclude that the coefficient of subsidiary stress dispersion will amplify with the increase of thickness or width or stiffness of back - up coat ; ( 4 ) the formula which can be used in conventional calculation has been deduced for calculating the coefficient of subsidiary stress dispersion and it also has been affirmed to be reasonable through the checking calculation ; the whole theory of compound two - layer foundation has been brought forward in this paper and it ' ll enrich the theory of composite foundation
針對以上問題本文做了以下一些工作並得到若干結論: ( 1 )提出了「復合雙層地基」的概念,並通過工程實例證明此概念的提出有其合理性和必要性; ( 2 )用彈性地基梁理論證實了復合雙層地基確有應力擴散效應,且擴散效應隨上覆硬層厚度、剛度的增加而增大,隨下臥層基床系數的增大而減小; ( 3 )建立了非線彈性、各向異性有限元模型,並以此為基礎分析了復合雙層地基的應力擴散效應,得到附加應力系數隨加固層厚度、寬度、剛度的增加而增大的結論; ( 4 )推導了可用於常規計算的復合雙層地基應力擴散系數公式,並代入工程實例進行了驗證。The study in the paper starts with beam distortions, and it treats the plastic deformation area as pure bending sect, rest of the beam as rigid bodies. according to different shapes of the external tendons, it divides into three structural forms familiar in projects, that is the beams with no deviator, with a deviator and with two deviators, and studies the relation between the deformation of the external prestressing tendons and that of the beams, and derives the formulas of the ultimate stress increment of external tendons. in the formulas, the ultimate angle corresponding to half of the plastic deformation area is considered as a variable parameter
本文首先從梁極限狀態下的變形入手,將塑性鉸區看作純彎段,將塑性鉸以外的區域看作剛體,按照體外預應力筋的形狀不同,分工程中最常見的三種體外結構形式,即無轉向塊的直線型體外筋混凝土梁、具有一個轉向塊的單折線型梁和具有兩個轉向塊的雙折線型梁,研究體外預應力筋變形和梁體的變形間的關系,推導出以極限狀態下塑性鉸區之半對應的轉角為參數的計算體外預應力混凝土簡支梁以及連續梁的體外筋應力增量計算公式,並進一步求得梁的極限承載力。Abstract : on the basis of general principles of mechanics and critical state soil mechanics theory, a theoretical formula determining the coefficient of earth pressure at rest for cohesionless soil is derived by means of combining hypoplasticity with critical state soil mechanics. the formula has a simple form and is only related to the effective angle of internal friction of soil. there is a slight difference between the calculated value of the formula and that of other formulae. the further investigation of the formula shows that it can be used to determine the coefficient of earth pressure at rest of cohesionless soil
文摘:在滿足一般力學原理和臨界狀態土力學理論的基礎上,本文將亞塑性理論與臨界狀態土力學相結合,推出了一個計算無粘性土靜止土壓力系數的理論公式.該公式形式簡單,僅與土的有效內摩擦角有關,其計算結果與常見的多個經驗公式的計算結果只有微小的差別.文中討論結果表明,該公式可用於確定無粘性土的靜止土壓力系數Based on the general mathematical models of multibody system dynamics such as the kinematics models of multibody dynamical systems, the ordinary differential equation models and the differential algebraic equation models of dynamics, general forms of the sensitivity equations of the systems are deduced by using direct differentiation method and adjoint variable method
基於通用的多體機械繫統運動學數學模型,常微分方程形式的動力學數學模型、微分/代數方程形式的動力學數學模型分別採用直接微分方法、伴隨變量方法推導出了系統的狀態靈敏度方程的通用形式。對于微分/代數形式的數學模型Based on an analysis of dynamic conditions for migration and precipitation of gold grains in water system and their diffusion in soil, this paper has advanced a discriminant formula for surfacce ore potential of gold anomalies from 1 : 50000 stream sediment survey, recounted methods for estimating the highest gold grade ores within the anomalies, calculated the discriminant indices for qinba area, and summed up index characteristics of ore - induced gold anomalies in 1 : 10000 soil survey, estimation formulae for orebody location as well as coefficients and constants of slope angles of various orders and grades
摘要在分析金粒在水系中運移、落淤和在土壤中擴散動力條件的基礎上,本文建立了五萬分之一水系沉積物測量金異常地表含礦性的判別公式,闡述了推算異常內礦石最高金品位的方法並計算了秦巴地區的判別指數;總結出萬分之一土壤測量礦致金異常的標志特徵、礦體定位的估算公式及各級次地形坡度角的系數和常數。Abstract : thermally induced stress and the relevant warpage cause by inappropriate mold design and processing conditions are problems that confounded the overall success of injection molding. a thermorheologically simple thermoviscoelastic two - dimension material model is used to simulate the residual stress and warpage within injection molded parts generated during the cooling stage of the injection molding cycle. the initial temperature field corresponds to the end of the filling stage. the fully time - dependent algorithm is based on the calculation of the elastic response at every time step. numerical results are discussed with respect to temperature and pressure
文摘:不均勻的熱殘余應力及其變形是注塑成型加工中常見的工程問題之一.應用熱流變簡單材料的二維熱粘彈本構方程得到的遞推公式,數值模擬了成型中的熱殘余應力及其翹曲變形,並用數值實驗討論了溫度、壓力對注塑件殘余應力及變形的影響,發現溫度變化不均勻是注塑件翹曲變形的最主要原因,其影響遠大於壓力的作用,與工程實驗的結論一致Based on the method of cell ( moc ), the effective elastic properties of resined fiber bundle with parallel or arbitrary orientation was studied, and a micro - mechanical model of resined plain - woven carbon fabric was established with the classical laminate theory, then, the method of calculation of the elastic moduli of resined plain - weave carbon fabric was presented, and can be extended to the whole carbon / phenolic composite
基於元胞法( moc )計算了預浸樹脂的平直以及任意取向的纖維束的有效彈性常數。基於經典層板理論用替代層法建立了預浸樹脂平紋機織碳布的細觀力學模型,進而給出了預浸氨酚醛樹脂的平紋機織碳布的彈性模量的計算方法,該方法可推廣到碳酚醛復合材料。The linear permanent magnet synchronous motor ( lpmsm ) has avoided the effects of the mechanical transmission chains from rotary motions to linear ones, and has strong electromagnetism thrust, lower cost, small electrical time constant and rapid response etc., which becomes one of the best executive machines in the high - precision and micro - feed servo system
由於永磁直線同步電動機消除了旋轉電機由旋轉運動到直線運動的機械傳動鏈的影響,且具有電磁推力強度高、損耗低、電氣時間常數小、響應快等特點,使其在高精度、微進給伺服系統中成為執行機構的最佳選擇之一。An on - line minimum - variance estimator was developed for thrust acceleration applied to orbit transfer using discrete - time radar measurements. the mass - flow - rate of propellant was selected as a state variant, which was estimated by employing an integral state model and ekf filter. the variation equations for measurement vector to mass - flow - rate have been established to linearize the discrete - time measurement equations. the algorithm has applied successfully to maneuver process in commanding satellite into geo - stationary orbit. the results show that the algorithm developed here can monitor and determine whether engine works well or failure precisely and quickly during orbit transfer process
飛行器軌道機動過程中,為跟蹤、定位機動目標和干預機動控制過程,需要統計處理離散的雷達觀測量實時估計推進發動機的推力,進而確定飛行器的瞬時軌道參數.本文所述演算法是該工程問題的探討和解決方案.文章建立了軌道機動過程中連續變質量運動模型和離散雷達量測模型,推進發動機的質量秒耗量作為表徵推力加速度的一個近似常量,應用擴展卡爾曼濾波對離散的雷達測量數據進行順序統計處理給出秒耗量的最小方差估計;文章詳細地推導了線性化量測模型的變分方程和觀測矩陣;模擬結果表明該演算法能快速、準確地估計推進發動機的質量秒耗量和向機動目標施加的實際推力2. to meet the demands of establishing a practical control system, this paper analyzed the main sensors " construction, performance, and work theory in a dynamic positioning system, discussed the output format of the sensors " signals and the feature of the signals " noise, introduced the common thrusters, and established the thruster ' s mathematics model
2 )為滿足建立實際控制系統的需要,分析了動力定位系統主要傳感器的構成、性能和工作原理,討論了傳感器信號的輸出形式及信號噪聲的特點,介紹了常用推進器,建立了推進器數學模型。In this paper, starting with the physical mechanics of land surface hydrologic process and the introduction of the theory in probability statistic distribution, an analytical expression of heterogeneous evapotranspiration efficiency is given which takes heterogeneous soil water content ' s subgrid scale spatial variability into account, through which the parameterization scheme of subgrid scale soil surface ' s evapotranspiration efficiency ( which is generally called mosaic method ) is modified to a statistic - dynamic scheme in which a whole heterogeneity of the grid region is considered
本文從陸面水文過程的物理機制出發,引進概率統計分佈理論,推導出一種由非均勻土壤含水量次網格尺度空間變率所形成的非均勻蒸發散率解析表達式,從而將通常的次網格尺度地表蒸散率的參數化方案( mosaic方法) ,改進為考慮網格區整體非均勻性的統計-動力參數化方案。In this paper, the backward simulation was summarizd at home andabroad, the characteristics of shell nosing were introduced, the theory and scheme of backward simul - ation of shell nosing was constructed, the determined methods of the boundary conditions were put forward in backward simulation for the processes of shell nosing
論述了推力矢量控制技術是提高空空導彈性能的核心技術,介紹了常用的三類推力矢量裝置,著重討論了燃氣舵式和擾流片式推矢裝置的特點、設計方法、性能及其優缺點.在此基礎上,研究了適用於氣動力/推力矢量復合控制的變結構控制系統及其開關函數的切換條件和飛行控制系統框圖.最後綜述了推力矢量裝置在第四代空空導彈上的應用情況This study introduces the energy consistent method ( ecm ), the ecm potential function, and the new formulae of vibrational force constants which are proposed by weiguo sun and hao feng [ 45, 46 ] recently. the ecm is applied to study the diatomic potential functions for some electronic ground states and excited states of gif, ch, bh, xeo, laf, 7lid, na7li, narb and krb molecules. the ecm potentials are compared with the experimental based rkr ( rydberg - klein - rees ) potentials, ipa ( inverted - perturbation - approach ) potentials, analytical morse potentials, and hms ( huxley - murrell - sorbie ) potentials
本文詳細地介紹了孫衛國和馮灝運用二階微擾理論所導出的高階振動力常數的求解公式、能量自洽法( energyconsistentmethod - ecm ) 、 ecm勢能函數的定義以及用能量自洽法計算穩定雙原子分子體系勢能函數的具體步驟,並將ecm方法推廣應用於cif 、 ch 、 bh 、 xeo 、 laf 、 ~ 7lid 、 na ~ 7li 、 narb和krb等九種異核雙原子分子的十二個電子基態和激發態的勢能函數。It is shown that when the exit area of secondary nozzle and the fuel / oxidizer ratio is fixed, the increase of mass flow rate of secondary flow lead to the decrease of velocity of mixed flow, and increase of total mass flow rate. the synthetical result of these two phenomenon cause the increase of thrust of rocket ejector, but the increasing magnitude is relatively small, indicating that these is no necessary to claim large bypass ratio in rocket ejector design. in the comparison between two configurations, the typical one has better performance, indicating the importance of pressure ratio
結果表明:在固定二次噴管出口面積和氧燃比的條件下,二次流(引射空氣流)流量的增加引起混合氣體出口速度的下降和總流量的增加,二者綜合作用使發動機推力增加,但增幅不大,表明在設計發動機結構和工作參數時,不必過分追求大的引射系數;兩種結構的性能對比分析表明了增壓比對引射火箭性能的提高具有重要意義;對引射火箭的熱力循環分析同樣表明,增壓比對于提高發動機性能非常關鍵。In order to meet the needs of real time computation of electric power system state estimation, the estimation algorithm based on decomposing the measurement of voltage scope and power scope and the estimation algorithm based on the measurement transformation of the equivalent current are brought forward and deduced in this thesis. these two algorithms all can make the jacobian matrix a constant matrix and they are stimulated
為了滿足電力系統狀態估計實時性的要求,本文首先提出並推導了可以使雅可比矩陣為常數陣的基於分解電壓測量量和功率測量量的估計演算法和基於等效電流測量變換的估計演算法,並對此進行了模擬。The paper is the project named " theory of dynamic precision synchronization traverse and research of realization methods for linear servo dual position loops system ( no - 50075057 ) " as the background, which is supported by national natural science foundation of china drive directly by linear permanent magnet synchronous ac motor, the controlled plant eliminates middle drive parts and avoids the effects of the mechanical transmission chains from rotary motions to linear ones
本文以國家自然科學基金資助項目《直線伺服雙位置環動態精密同步進給理論和實現方法研究( no 50075057 ) 》為背景,針對直線同步進給提出了一種新的控制方案:模型參考自適應控制。機床採用永磁直線同步電動機直接驅動,省掉了中間的傳動環節,消除了機械傳動鏈的影響;又因永磁直線同步電動機採用高能永磁體,具有電磁推力強度高、損耗低、電氣時間常數小、響應快等特點。And this driving type results in the disadvantages of metro project such as the high cost of construction and maintenance, the big noise of vibration. the linear metro, which is droved by linear induction motor ( lim ), needn ’ t intermediate gearing and is droved to advance directly by the electromagnetic thrust between primary and secondary of lim. its force of traction is no longer restricted with the track adherence and the wheel only plays the support and guidance role
電磁氣隙是直線感應電動機的一個重要參數,氣隙的變化會直接影響到電磁推力、初級電流等電機特性,而推力和電流對地鐵的穩定運行起著至關重要的作用,所以對地鐵中直線感應電動機的性能及氣隙變化對電機性能的影響進行分析研究具有非常重要的意義。分享友人