SUBROUTINE lpm_extend_tails !------------------------------------------------------------------------------! ! Current revisions: ! ------------------ ! ! ! Former revisions: ! ----------------- ! $Id: lpm_extend_tails.f90 850 2012-03-15 12:09:25Z raasch $ ! ! 849 2012-03-15 10:35:09Z raasch ! initial revision (former part of advec_particles) ! ! ! Description: ! ------------ ! Add the current particle positions to the particle tails. !------------------------------------------------------------------------------! USE control_parameters USE particle_attributes IMPLICIT NONE INTEGER :: i, n, nn REAL :: distance distance = 0.0 DO n = 1, number_of_particles nn = particles(n)%tail_id IF ( nn /= 0 ) THEN ! !-- Calculate the distance between the actual particle position and the !-- next tailpoint IF ( minimum_tailpoint_distance /= 0.0 ) THEN distance = ( particle_tail_coordinates(1,1,nn) - & particle_tail_coordinates(2,1,nn) )**2 + & ( particle_tail_coordinates(1,2,nn) - & particle_tail_coordinates(2,2,nn) )**2 + & ( particle_tail_coordinates(1,3,nn) - & particle_tail_coordinates(2,3,nn) )**2 ENDIF ! !-- First, increase the index of all existings tailpoints by one IF ( distance >= minimum_tailpoint_distance ) THEN DO i = particles(n)%tailpoints, 1, -1 particle_tail_coordinates(i+1,:,nn) = & particle_tail_coordinates(i,:,nn) ENDDO ! !-- Increase the counter which contains the number of tailpoints. !-- This must always be smaller than the given maximum number of !-- tailpoints because otherwise the index bounds of !-- particle_tail_coordinates would be exceeded IF ( particles(n)%tailpoints < maximum_number_of_tailpoints-1 ) & THEN particles(n)%tailpoints = particles(n)%tailpoints + 1 ENDIF ENDIF ! !-- In any case, store the new point at the beginning of the tail particle_tail_coordinates(1,1,nn) = particles(n)%x particle_tail_coordinates(1,2,nn) = particles(n)%y particle_tail_coordinates(1,3,nn) = particles(n)%z particle_tail_coordinates(1,4,nn) = particles(n)%class ! !-- Increase the age of the tailpoints IF ( minimum_tailpoint_distance /= 0.0 ) THEN particle_tail_coordinates(2:particles(n)%tailpoints,5,nn) = & particle_tail_coordinates(2:particles(n)%tailpoints,5,nn) + dt_3d ! !-- Delete the last tailpoint, if it has exceeded its maximum age IF ( particle_tail_coordinates(particles(n)%tailpoints,5,nn) > & maximum_tailpoint_age ) THEN particles(n)%tailpoints = particles(n)%tailpoints - 1 ENDIF ENDIF ENDIF ENDDO END SUBROUTINE lpm_extend_tails