[FLASH-BUGS] bug in hydro flash2.3

[Markus Gross]

Hi!

I presume my earlier mail now went through fine.

On another topic (maybe I am lucky and I catch two birds with one stone ...):


line 96-line 100:

!!****f* source/hydro/explicit/splot/ppm/interp
! assemble the left and right interface values using the quartic polynomial,
! Eq. 1.6 from Colella & Woodward
    
    do i = 2, nzn6+1
        ar(i)  = a (i) + coeff5(i) * scrch1(i+1) + coeff3(i) * dela(i+1)
       ar(i)  = ar(i) + coeff4(i) * dela(i)
       al(i+1)= ar(i)
    end do


This causes a runtime error. This one was bothering for quite a while, but it 
is so tempting to avoid errors but simply ignoring compiler flags ;-)

when I look into:

!!****f* source/hydro/explicit/splot/ppm/coeff

I find that coeff5(nzn6+1) and coeff3(nzn6+1) are actually not computet!

    do i = 2, nzn6
       temporary = 1. / ( scrch1(i) + scrch1(i+2) )
       coeff3(i) = -temporary * dx(i)   * scrch1(i)   / scrch3(i+1)
       coeff4(i) =  temporary * dx(i+1) * scrch1(i+2) / scrch2(i+1)
       coeff5(i) = dx(i) - 2.e00 * (dx(i+1) * coeff3(i) + dx(i) * coeff4(i))
       coeff5(i) = coeff5(i) / scrch1(i+1)
    end do

and hence not initialized!

I will dig out my copy of Colella & Woodward tonight still, but any hint is 
of course appreciated.

Regards,

Markus.

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Markus Gross AMIMechE BEng (Hons.) Mechanical Engineering

Heriot Watt University Edinburgh
School of Engineering and Physical Sciences
James Nasmyth Building
Edinburgh
EH14 4AS
UK

Member of  IMechE, SPIE, CSME and VDI
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further contact:

Phone   : +44 (0) 131 451 4737

UNiX talk: talk markus at lasersim.mce.hw.ac.uk

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