<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><div class=""></div><div class=""><br class=""></div><div class="">Our purpose is to run the code at 10 mach number. I wonder if you changed the Solver yourself to make the code stable or just use solver in the flash4. If the latter, could you please give some advice about the features and the solver you used?</div><div class=""><br class=""></div><div class="">If everyone have some suggestion about the high mach number using the un_split method in the Stir unit. Please connect me!</div><div class="">Thank you all!</div><div class="">Best wishes!</div><div class=""><br class=""></div><div><br class=""><blockquote type="cite" class=""><div class="">下面是被转发的邮件：</div></blockquote><blockquote type="cite" class=""><br class="Apple-interchange-newline"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">发件人: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">Christoph Federrath <<a href="mailto:christoph.federrath@gmail.com" class="">christoph.federrath@gmail.com</a>><br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">主题: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class=""><b class="">回复：[FLASH-USERS] Supersonic Turbulence using the PPM method</b><br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">日期: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">2021年6月2日 GMT+8 下午5:47:12<br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">收件人: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">Tristan <<a href="mailto:juwj@mail2.sysu.edu.cn" class="">juwj@mail2.sysu.edu.cn</a>><br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">抄送: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class=""><a href="mailto:flash-users@flash.uchicago.edu" class="">flash-users@flash.uchicago.edu</a><br class=""></span></div><br class=""><div class=""><div class=""><br class="">Hi Tristan,<br class=""><br class="">for PPM, you can try nriem = 1000, which helped sometimes (in the past). Also reducing cfl helps. However, there is a limit to those tweaks. I would suggest to try the unsplit solvers. Dongwook Lee implemented a number of features to make them more stable, such as shock detection and automatic reduction of the cfl. We are using a different solver altogether (Waagan et al. 2011, JCP, based on work by Bouchut et al., which is not (yet) in the public flash repository though.<br class=""><br class="">Best regards,<br class="">Christoph<br class=""><br class=""><blockquote type="cite" class="">On 2 Jun 2021, at 19:21, Tristan <<a href="mailto:juwj@mail2.sysu.edu.cn" class="">juwj@mail2.sysu.edu.cn</a>> wrote:<br class=""><br class="">Hello,everyone:<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>I am working on a simulation<span class="Apple-tab-span" style="white-space:pre"> </span>with high Mach number turbulence using the StirFromFile unit, I using the forcing_generator.F90 to generate the Driving force seed with the Mach at 12(by changed the st_energy). But I did’t know how to choose a suitable Solver for the Stir unit. <br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>I tried the split PPM solver, and the two parameters to the flash.par:<br class="">```<br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>use_steepening = .false. # use contact steepening (originally for PPM) <br class=""><span class="Apple-tab-span" style="white-space:pre"> </span>hybrid_riemann = .true.<br class="">```<br class="">My program broke down quickly, and the error output is:<br class=""><br class="">Terminating execution.<br class="">DRIVER_ABORT: Nonconvergence in subroutine rieman<br class="">application called MPI_Abort(MPI_COMM_WORLD, 1) - process 46<br class=""><br class="">I also attached the flash.par and the output file for you to check my work. If someone have a better Solver choice in Supersonic (Mach above 12) turbulence simulation. Please help me! <br class="">Thanks<br class="">Best wishes!<br class=""><br class=""><flash.par><slurm-4341014.out><br class=""></blockquote><br class=""><br class=""></div></div></blockquote></div><br class=""></div></body></html>