<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="">Oh,I forgot this useful PARAMETER</div>It solved my question, @<span style="font-family: -webkit-system-font, "Helvetica Neue", Helvetica, sans-serif;" class="">Klaus Weide</span><span style="font-family: -webkit-system-font, "Helvetica Neue", Helvetica, sans-serif;" class=""> , Thanks you</span><div class=""><font face="-webkit-system-font, Helvetica Neue, Helvetica, sans-serif" class="">Best wishes!<br class=""></font><div class=""><div><br class=""><blockquote type="cite" class=""><div class="">Begin forwarded message:</div><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="">From: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">Klaus Weide <<a href="mailto:klaus@flash.uchicago.edu" class="">klaus@flash.uchicago.edu</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="">Subject: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class=""><b class="">Re: [FLASH-USERS] How can I add density property to the particle</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="">Date: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">May 27, 2021 at 11:56:38 PM GMT+8<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="">To: </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="">On Thu, 27 May 2021, Tristan wrote:<br class=""><br class=""><blockquote type="cite" class="">I am doing a simulation about the characteristic of the high mach <br class="">turbulence. I want to add some passive Lagrangian particles into the <br class="">simulation. But the default properties of particles include velocity and <br class="">position, not the density. I want to know the density of the trajectory <br class="">the particles draw. Maybe use the Runge-Kutta method.<br class=""><br class="">I have reading the guide and add the two line to the ParticlesMain unit Config :<br class=""><br class="">```<br class="">PARTICLEPROP dens REAL<br class="">PARTICLEMAP TO dens FROM VARIABLE dens<br class="">```<br class=""></blockquote><br class="">You need something like this in addition:<br class=""><br class=""> D particle_attribute_1 specification of which particle_attributes <br class=""> D & to output. The same description is valid for particles_attributes_2...etc<br class=""> PARAMETER particle_attribute_1 STRING "dens"<br class=""> PARAMETER particle_attribute_2 STRING "temp"<br class=""> ...<br class=""><br class=""><br class="">Klaus<br class=""><br class=""></div></div></blockquote></div><br class=""></div></div></body></html>