Help with using quadrilateral grids

[Praveen C]

Hello

I am trying to write my first code with quad grids.

https://github.com/cpraveen/chpde/tree/master/euler_2d/cylinder

It is set up to solve euler equations exterior to a cylinder. I am using roe solver for mapped grids that is included in clawpack

https://github.com/cpraveen/chpde/blob/master/euler_2d/cylinder/Makefile

  $(CLAW)/riemann/src/rpn2_euler_mapgrid.f90 \
  $(CLAW)/riemann/src/rpt2_euler_mapgrid.f90 \
  $(CLAW)/riemann/src/euler_roe_solver_mapgrid.f90 \
  $(CLAW)/riemann/src/getquadinfo_mapgrid.f90

I believe I have taken care of setting up aux arrays and bc. But when I run even first order method, the code quickly fails with negative sound speeds.

Are these Riemann solvers supposed to work ?

Can somebody glance through my files and see if they spot any mistake ?

Here is the error

CLAW2EZ: Frame    0 output files done at time t =  0.0000D+00

 3-wave is transonic
 3-wave is transonic
 1-wave is transonic
 3-wave is transonic
 3-wave is transonic
 Roe solver :
c2 .lt. 0;  -0.35970417E+02
 ixy =            1
 enth =    67.558869504496357    
 Called from rpn2
 
  0.8591302689298141E+00  0.8591302689298141E+00
 -0.1982120369244459E+02  0.1982120369244459E+02
 -0.1524731924475515E+02 -0.1524731924475515E+02
  0.1454441822214376E+03  0.1454441822214376E+03

Thanks

praveen