! heat_flow program to determine the temperature of the ground ! around a tank full of LNG. ! Look at 200 points, each a quarter foot apart, going away from the tank. dimension u(200), unew(200) data u/200*60.0/ ! Initial temperature of 60 degrees tc = 2.6 ! The termal conductivity (or K) of the ground c = 0.2 ! The heat capacity or specific heat rho = 132.0 ! The density of the ground h = .25 ! The stepsize in feet for this calculation timestep = .25 ! The timestep in hours temperature = -258.0 ! The temperature of LNG r = tc*timestep/(c*rho*h*h) ! a constant, the coefficient of first term n = 200 ! The number of points and equations. nm = n-1 ! n minus 1 part = 1.0 - 2.0*r ! The coefficient of u^j_i do j = 1, 1000 unew(1) = r*temperature+part*u(1)+r*u(2) ! boundary condition do i = 2, nm unew(i) = r*u(i-1)+part*u(i)+r*u(i+1) enddo u(n) = r*u(nm)+part*u(n)+r*u(n) do k = 1, nm u(k) = unew(k) enddo enddo print 5,u 5 format (4f14.4) stop end