The Non-steady Seepage Cut Away From The Well Method For Solving Computer And Fast For Parametric Study

The thesis have three parts, it are: (1)Math basic about computer simulation of isolated well and improve calculation precise; (2)Computer simulation of isolated well (3)Aquifer parameter of solution by using isolated well method In chapter one, the author introduces groundwater progress compendium, put forward a important method of groundwater flow calculation that is method, elicit concept of isolated well method, depiction model and calculation equation of isolated well method. The thesis put forward three basic theory problem of solving computer simulation of isolated well method. 《A study on computer implement and solution parameter of shortcut method by isolated well method in unsteady seepage flow》is theme, the author try to solve the following difficult problems: 1) Math basic about computer simulation of isolated well and improve calculation precise; 2) Contain ability and calculation precision during the course of using isolated well method. 3) Innovation and exploitation of software packet 4) Solution parameter of shortcut method by isolated well method In chapter two, the thesis analyze mathematical problem during the course of computer simulation of isolated well method one by one. It includes solution method and root's initial value extent of Bessel functions and transcendental equations, computer solution of series, integral of numerical value. It comes into being more integrity mathematical base of computer simulation of isolated well method. But it can know mathematical problem, calculation method during the course of computer simulation. It is propitious to make program and read program. At the same time, the chapter solves two problems, 1. Feasibility problem in computer simulation of isolated well method. The chapter introduce concept of slow constringency series, analyze some character about slow constringency series. It will bring out larger calculation error when we calculate slow constringency series by computer. Thus it need make use of others method according to its character because the calculation of slow constringency series can't adopt quondam series. But the calculation equation of isolated well method isn't slow constringency series so that we can get approximation, which satisfy a certain extent precision. It brings out theory gist in computer simulation of isolated well method. 2. It solve root's initial value extent of every transcendental equation by using isolated well method. It usually adopt dichotomy in solving every transcendental equations, need make certain root's initial value extent through figures. The chapter analyzes two border roots'distance when independent variable becomes smaller or larger. It is the same that we solve λ_n which is root n of equations, initial value extent of root n+1 is [λ_n+3, λ_n+4].It can avoid skip over roots and search roots so that it enhance calculation velocity by using computer simulation of isolated well method. In chapter three, the thesis study precision control in computer simulation of isolated well method, finish two aspects work, 1.The thesis gives more systemic theory and method of series truncation errors estimate. To positive constringency series, the author estimates its truncation errors through introducing ratio and extract of series, put forward estimate method of interleaving series and ordinarily series. In the end, the author gives out estimate equations of power series truncation errors in constringency series range. It has important significance for functions solve theory of numerical value analysis, which has instruct significance for control calculation precision and improve calculation precision in computer simulation of series. 2.The author gets estimate equations of truncation errors in calculation equations of isolated well method which may has integral or hasn't integral through mathematic prove method and computer calculation. First, the author introduce several lemma, we can know some characters of zero rank and one rank Bessel function, functions character in calculation equations of isolated well method. The follow, the author prove estimate form of truncation errors in several calculation equations which hasn't integral. On the other hand, the author introduce average ratio of series to calculate estimate numerical value of truncation errors. Because calculation equations of isolated well method, which contain integral may between calculation equations of isolated well method, which hasn't integral, we can confirm truncation errors. From the estimate results of the chapter, its truncation errors aren't as much again than absolute value item n+1 is, it is benefit for computer simulation and advance calculation precision in theory. In chapter four, the author analyze calculation precision, introduce interior product concept, get four perpendicular system through analyzing function character, it has better foundation for further study. The author gets several math model of familiar isolated well method through math model superposition. When coefficient of water-level conductivity changes along with time, it can obtain half-analytic solution. It include math model I, math model I-1, math model II-1, math model III-1, math model IV-1 and math model IV. Except for math model II-1, its expression lack one factor E (I , n) which compare with series, the factor relate to coefficient of water-level conductivity each period of time. When coefficient of water-level conductivity each period of time is same, the factor is 1.Thus the equations become isolated well method equations. Part equations of isolated well method are regarded as special examples. The author introduces math model II of isolated well method when he study math model II-1. That is math model of isolated well method when it has leakage from upper part and has function of initial water level. But the author gets analytical solution. In chapter five, the author carries out computer simulation of isolated well method equations by using C++ language. First, the author finishes computer simulation of Bessel function. Second, the author accomplishes computer simulation of solving transcend equations solution. Further, the author make program about every water level equation and pumping volume, adoptconclusion of control calculation precision as stop condition, improve calculation precision. It include make program on calculation equations of isolated well method which may has integral or hasn't integral. These programs are given by functions. Then the author carries out seepage flow calculation, join up related functions with project in C++ language. The author utilizes calculation equations of coefficient of water-level conductivity, make program of water level equations and pumping volume equations. At one time, the author finishes the calculation of computer simulation by project of C++ language, which can improve precision. It adopt simply interface which can man-machine conversation, input demand parameter, accomplish seepage flow calculation. In the end, the author draws some conclusions with a model. The author finished calculation software packet of isolated well method in Microsoft Visual C++ platform. In chapter six and seven, the author study parameter calculation problems by using isolated well method. Through apply type-curve method, liner graphic method, trial calculation method and computer iterative method in some isolated well method, the author get some methods which are "flow rate-time method of isolated well method under the condition of no discharge from upper and lower aquifer and fixed water level in well", "drawdown-time method of isolated well method under the condition of fixed water yield and initial level water level", "linear graphic method of isolated well method under the condition of no discharge from upper and lower aquifer and fixed water level in well", "trial calculation method of isolated well method under the condition of no discharge from upper and lower aquifer and fixed water level in well", "computer iterative method of isolated well method under the condition of no discharge from upper and lower aquifer and fixed water level in well". The author solve difficult aspects by Mathematica soft and give calculation steps. It is a new method. In chapter eight, it is summing-up.