******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Hi, I tried to run Sod problem using Nektar. The solver information is as follows, <SOLVERINFO> <I PROPERTY="EQType" VALUE="EulerCFE" /> <I PROPERTY="Projection" VALUE="DisContinuous" /> <I PROPERTY="AdvectionType" VALUE="WeakDG" /> <I PROPERTY="TimeIntegrationMethod" VALUE="ForwardEuler" /> <I PROPERTY="UpwindType" VALUE="HLLC" /> <I PROPERTY="LocalTimeStep" VALUE="True" /> <I PROPERTY="ShockCaptureType" VALUE="NonSmooth" /> </SOLVERINFO> The information of expansion is <E COMPOSITE="C[1]" NUMMODES="3" FIELDS="rho,rhou,rhov,E" TYPE="MODIFIED" /> The mesh is generated by Gmsh. For simplicity, I use qausi-structured mesh with dx=0.0047 and dy=0.0036. According to my knowledge of numerical scheme, CFL is usually between 0.1 and 0.5. However, I found out that CFL must be 0.01 to ensure stable simulation. Why is CFL so small in Nektar? Chengeng