numerical adj. 數(shù)字的;數(shù)值的;用數(shù)字表示的。 (a) numerical order 號(hào)數(shù)。 a numerical statement 統(tǒng)計(jì)。 the numerical strength 人數(shù),兵數(shù)。 adv. -ly 用數(shù)字,在數(shù)字上。
dispersion n. 1.分散,散開;散布,傳播;離散。 2.【物理學(xué)】彌散,色散;【化學(xué)】分散作用;被分散物;分散相,分散體系;【醫(yī)學(xué)】(炎癥等的)消散;【統(tǒng)計(jì)學(xué)】離中趨勢(shì)。 3.〔the D-〕 (猶太人的)離散異邦。 the dispersion of heat 熱的擴(kuò)散。 the dispersion of an assembly 集會(huì)的解散。 dispersion on the ground 炮彈在地面上的散布。
Simulation research on numerical dispersion for modeling of wave guide devices by fdtd 法建模波導(dǎo)器件時(shí)數(shù)值色散的仿真研究
The suppression of numerical dispersion and improvement of absorbing boundary conditions in forward modeling of gpr 地質(zhì)雷達(dá)正演中的頻散壓制和吸收邊界改進(jìn)方法
First , we reviewed the finite - difference time - domain yee ' s method . the difference equations , the stability condition , numerical dispersion characteristics , absorbing boundary conditions , incident wave source conditions and the calculation of the frequency - dependent scattering parameters are discussed 首先本文回顧了時(shí)域有限差分yee算法,包括時(shí)域有限差分的差分方程、穩(wěn)定性條件、數(shù)值色散特性、吸收邊界條件,激勵(lì)源的設(shè)置以及散射參數(shù)的計(jì)算等。
In chapter one , we propose a new mixed method called characteristics mixed finite element method for a convection - dominated diffusion problems with small parameter e : we handle the convection part whth backward difference scheme along the characteristics , obtain much smaller time - trunction errors and avoid numerical dispersion on the front of the peak curve of the flow : we use a lowest order mixed finite element method to deal with the diffusion part , so this scheme can approximate the unknow function and its following vector with high accuracy at the same time 第一章中我們對(duì)小參數(shù)對(duì)流占優(yōu)擴(kuò)散問題提出了新的數(shù)值方法? ?特征混合有限元方法,即對(duì)方程的對(duì)流部分采用沿特征線的后退差分格式求解,以保證較小的截?cái)嗾`差限并避免了在流動(dòng)的鋒線前沿?cái)?shù)值彌散現(xiàn)象的出現(xiàn);對(duì)流動(dòng)的擴(kuò)散部分采用最低次混合元方法求解,以保證格式對(duì)未知函數(shù)及伴隨向量的同時(shí)高精度逼近。由于該方法中檢驗(yàn)函數(shù)可取分片常數(shù),此格式在某種意義上具有局部守恒性質(zhì)。
Important missing aspects are : turbulent flow , numerical discretization techniques specially the relevant and difficult topic of numerical treatment of advection and related numerical methods of solution , variable property fluids , boundary layers , stability , etc . rather , it focuses on more primitive and fundamental issues of numerical treatment of advective equation and proper formulation of initial boundary value ( ib vp ) . numerical problems associated with advective dominated transport include spurious oscillation , numerical dispersion , peak clipping , and grid oriention . however , the key of numerical solution of three - dimensional advective problem is searching for a high - precision interpolating function , which can keep the computational stability and low damping 3 、針對(duì)三維純對(duì)流方程提出了實(shí)用的擬協(xié)調(diào)單元模式,并與線性插值模式和協(xié)調(diào)單元模式比較后表明,在物理量大梯度變化的情況下,線性插值模式會(huì)產(chǎn)生較大的數(shù)值阻尼,導(dǎo)致解的失真;協(xié)調(diào)單元模式具有極高的計(jì)算精度和良好的計(jì)算穩(wěn)定性,還可較好地克服數(shù)值阻尼,但由于計(jì)及物理量的二階導(dǎo)數(shù)項(xiàng),計(jì)算工作量大,邊界條件給定尚存在一定的困難;而擬協(xié)調(diào)單元模式不僅具有協(xié)調(diào)單元模式計(jì)算精度高的優(yōu)點(diǎn),還避免了物理量的二階導(dǎo)數(shù)項(xiàng),可大大地減少計(jì)算工作量。