{"id":380766,"date":"2024-08-28T00:47:50","date_gmt":"2024-08-28T00:47:50","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mixing-of-gases-no-combustion\/"},"modified":"2024-08-28T00:47:50","modified_gmt":"2024-08-28T00:47:50","slug":"mixing-of-gases-no-combustion","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mixing-of-gases-no-combustion\/","title":{"rendered":"mixing of gases, no combustion"},"content":{"rendered":"

<div>I want to simulate the following problem:<\/div><div>I want to study the mixture of two gases, but without combustion. the flows are supersonic and there are a total of three inlets, two of which with oxidizer and one with fuel and the gases are not premixed with the other one. I only know their pressure, which is 6 Pa for oxidizer and 12 Pa for fuel.<\/div><div>I have the following procedure: <\/div><div>Sover: Density-based, Absolute velocity formulation, steady,  2D planar, no gravity<\/div><div>Energy: on<\/div><div>Viscous model: Spalart-Allmaras<\/div><div>Speices Model: Species Transport (Ractions (volumetic) -uncheked ; Options( diffusions)-uncheked;)<\/div><div>           Mixture Properties:  Mixture species: air and h2<\/div><div>           denisty: ideal-gas<\/div><div>           cp- mixing law<\/div><div>           thermal conductivity- constant 0.0454<\/div><div>           viscosity- constant 1.72e-05<\/div><div>          mass diffusivity-constant dilute approx 2.88e-05<\/div><div> <\/div><div>Boundary conditions: <\/div><div>inlet air: pressure inlet: gauge tot. press. 600000<\/div><div>supersonic\/initial gauge press: 600000<\/div><div>thermal: 300<\/div><div>species: h2: 0<\/div><div> <\/div><div>inlet h2: pressure inlet: gauge tot. press. 1200000<\/div><div>supersonic\/initial gauge press: 1200000<\/div><div>thermal: 290<\/div><div>species: h2: 1<\/div><div> <\/div><div>outlet: gauge pressure: 100000<\/div><div>thermal: 300<\/div><div>species: h2: 0<\/div><div> <\/div><div>operating pressure: 0<\/div><div> <\/div><div>Solution methods: <\/div><div>Formulation: implicit<\/div><div>Flux-type: roe-fds<\/div><div>Spatial discretization: gradient: least squares cell based<\/div><div>         flow: second order upwind<\/div><div>         modified turbulent viscoisty: second order upwind<\/div><div>         pseudo time method: off<\/div><div> <\/div><div>Initialization: hybrid (no patch)<\/div><div>Iterations steps: 10000<\/div><div> <\/div><div>when I run the simulation, the residuals go high (higher than e+04) and the simulation stops. <\/div><div>what have I done wrong? What do you thinnk of my procedure? Is it plausible?<\/div><\/p>\n","protected":false},"template":"","class_list":["post-380766","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t