Математическая и численная модели термического состояния бунта хлопка-сырца с учетом теплообмена с окружающей средой и внутреннего тепловыделения
- № 3(9) 2017
Страницы:
55
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62
Язык: русский
Аннотация
Приводится математическая модель процесса теплопередачи в трехмерном объеме в условиях теплообмена с окружающей средой и внутреннего тепловыделения согласно экспоненциальному закону. Форма бунта принята в виде прямоугольного параллелепипеда, на нижней границе которого наложено условие второго рода, на верхней границе – условие третьего рода, а на боковых гранях – условия первого рода. Для численного решения задачи использован дифференциально-разностный метод. Дискретизация свободных переменных и искомой функции произведена в три этапа: по времени и абсциссе, по ординате и по аппликате. В первых двух этапах реализован метод прямых, а на последнем этапе – метод конечных разностей с привлечением прогоночного процесса. Обеспечены первый порядок точности аппроксимации по времени и второй – по декартовым координатам. Представлены примеры результатов вычислительного эксперимента.
A mathematical model of the heat transfer process in a three-dimensional volume is presented in the conditions of heat exchange with the environment and internal heat release according to the exponential law. The form of the mass is taken in the form of a rectangular parallelepiped, on the lower boundary of which a condition of second type, on the upper boundary — a condition of the third type, and on the lateral faces — conditions of the first type are imposed. A differential-difference method was used to solve the problem numerically. The discretization of the free variables and the desired function is carried out in three stages: due to time and abscissa, due the ordinate and due to the applicate. In the first two stages, the method of lines, and at the last stage — the method of finite differences with the involvement of the sweeping process is implemented. The first order of accuracy of approximation in time and the second is in Cartesian coordinates is provided. Examples of the results of a computational experiment are presented.
Tashqi muhit bilan issiqlik almashinuvi hamda eksponensial qonun bo’yicha ichki issiqlik ajralib chiqishi sharoitidagi uch o’lchamli massada (paxta bunti misolida) issiqlik almashinuvi jarayonining matematik modeli keltirilmoqda. Bunt to’g’ri burchakli parallelepiped shaklida qaralgan bo’lib, pastki asosiga ikkinchi jins, ustki asosiga uchinchi jinsva yon yoqlariga birinchi jins chegara shartlari qo’yilgan. Masalani sonli yechish uchun differensial –ayirmali usuldan foydalanilgan. Erkli o’zgaruvchilarni va noma’lum funksiyani diskretlash uch bosqichda amalga oshirilgan: vaqt va absissa bo’yicha, ordinate bo’yicha, applikata bo’yicha. Dastlabki ikki bosqichda to’g’ri chiziqlar usulidan, so’nggi bosqichda esa progonka jarayoni jalb etilgan holda chekli ayirmalar usulidan foydalanilgan. Vaqt bo’yicha birinchi darajali, dekart koordinatalari bo’yicha ikkinchi darajali approksimatsiya aniqligi ta’minlangan. Hisob tajribalari natijalari keltirilmoqda.
A mathematical model of the heat transfer process in a three-dimensional volume is presented in the conditions of heat exchange with the environment and internal heat release according to the exponential law. The form of the mass is taken in the form of a rectangular parallelepiped, on the lower boundary of which a condition of second type, on the upper boundary — a condition of the third type, and on the lateral faces — conditions of the first type are imposed. A differential-difference method was used to solve the problem numerically. The discretization of the free variables and the desired function is carried out in three stages: due to time and abscissa, due the ordinate and due to the applicate. In the first two stages, the method of lines, and at the last stage — the method of finite differences with the involvement of the sweeping process is implemented. The first order of accuracy of approximation in time and the second is in Cartesian coordinates is provided. Examples of the results of a computational experiment are presented.
Tashqi muhit bilan issiqlik almashinuvi hamda eksponensial qonun bo’yicha ichki issiqlik ajralib chiqishi sharoitidagi uch o’lchamli massada (paxta bunti misolida) issiqlik almashinuvi jarayonining matematik modeli keltirilmoqda. Bunt to’g’ri burchakli parallelepiped shaklida qaralgan bo’lib, pastki asosiga ikkinchi jins, ustki asosiga uchinchi jinsva yon yoqlariga birinchi jins chegara shartlari qo’yilgan. Masalani sonli yechish uchun differensial –ayirmali usuldan foydalanilgan. Erkli o’zgaruvchilarni va noma’lum funksiyani diskretlash uch bosqichda amalga oshirilgan: vaqt va absissa bo’yicha, ordinate bo’yicha, applikata bo’yicha. Dastlabki ikki bosqichda to’g’ri chiziqlar usulidan, so’nggi bosqichda esa progonka jarayoni jalb etilgan holda chekli ayirmalar usulidan foydalanilgan. Vaqt bo’yicha birinchi darajali, dekart koordinatalari bo’yicha ikkinchi darajali approksimatsiya aniqligi ta’minlangan. Hisob tajribalari natijalari keltirilmoqda.