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New Multiphysics Solvers

LS-DY­NA in­cludes three new solvers for mul­ti­physic pur­pos­es :

  • In­com­press­ible CFD (ICFD)
  • Elec­tro­mag­net­ics (EM)
  • CESE/­ Com­press­ible CFD and Chem­istry

Pur­su­ing LSTC's ob­jec­tive of of­fer­ing a uni­fied sim­u­la­tion en­vi­ron­ment for an al­ways wider range of ap­pli­ca­tions, those three new solvers are au­to­mat­i­cal­ly in­clud­ed and avail­able for any reg­is­tered DY­NA user (start­ing from R7, dou­ble pre­ci­sion ex­e­cuta­bles on­ly).

In­com­press­ible CFD

The adop­tion of new ma­te­ri­als in the de­sign of lighter and more fu­el ef­fi­cient cars and the in­tro­duc­tion of mov­able parts for ac­tive aero­dy­nam­ic con­trol cre­ate new chal­lenges to the tra­di­tion­al mod­el of sep­a­rat­ed CFD/­struc­tur­al me­chan­ics de­part­ments in the au­to­mo­tive in­dus­try. New struc­tur­al ma­te­ri­als may ex­hib­it un­pre­dictable be­hav­iors un­der flow loads and tem­per­a­tures at road test con­di­tions.

It is LSTC's be­lief that ful­ly cou­pled ther­mal/­struc­tur­al/­CFD sim­u­la­tions will be­come in­creas­ing­ly nec­es­sary to avoid last minute sur­pris­es in the de­sign chain. LS-DY­NA of­fers a sim­ple so­lu­tion to in­cor­po­rate the struc­tur­al mod­el in­to the CFD analy­sis us­ing some of the most state of the art Fi­nite el­e­ment tech­nol­o­gy ap­plied to flu­id me­chan­ics. The ICFD solver can run as a stand alone for pure CFD ap­pli­ca­tions (the study of drag lift around bluff body and ve­hi­cles for ex­am­ple), or be cou­pled to the ther­mal and struc­tur­al me­chan­i­cal prob­lems for lin­ear and non-lin­ear com­plex FSI and con­ju­gate heat trans­fer ap­pli­ca­tions. It al­so makes use of an au­to­mat­ic mesh gen­er­a­tor for the flu­id vol­ume thus great­ly re­duc­ing the cost of set­ting up the mod­el. For more de­tails, please re­fer to the as­so­ci­at­ed menu links.

 

  Elec­tro­mag­net­ics

The Elec­tro­mag­net­ism solver solves the Maxwell equa­tions in the Ed­dy cur­rent (in­duc­tion-­dif­fu­sion) ap­prox­i­ma­tion. This is suit­able for cas­es where the prop­a­ga­tion of elec­tro­mag­net­ic waves in air (or vac­u­um) can be con­sid­ered as in­stan­ta­neous. There­fore, the wave prop­a­ga­tion is not solved. The main ap­pli­ca­tions are mag­net­ic met­al form­ing or weld­ing, in­duced heat­ing, and so forth. The EM mod­ule al­lows the in­tro­duc­tion of a source of elec­tri­cal cur­rent in­to sol­id con­duc­tors and the com­pu­ta­tion of the as­so­ci­at­ed mag­net­ic field, elec­tric field, as well as in­duced cur­rents. The EM solver is cou­pled with the struc­tur­al me­chan­ics solver (the Lorentz forces are added to the me­chan­ics equa­tions of mo­tion), and with the struc­tur­al ther­mal solver (the ohmic heat­ing is added to the ther­mal solver as an ex­tra source of heat). The EM fields are solved us­ing a Fi­nite El­e­ment Method (FEM) for the con­duc­tors and a Bound­ary El­e­ment Method (BEM) for the sur­round­ing air/­in­su­la­tors. Thus no air mesh is nec­es­sary. For more de­tails, please re­fer to the as­so­ci­at­ed menu links.

 

 

 CESE/­ Com­press­ible CFD

The CESE solver is a com­press­ible flow solver based up­on the Con­ser­va­tion El­e­ment/­So­lu­tion El­e­ment (CE/­SE) method, orig­i­nal­ly pro­posed by Dr. Chang in  NASA Glenn Re­search Cen­ter. This method is a nov­el nu­mer­i­cal frame­work for con­ser­va­tion laws. It has many non-tra­di­tion­al fea­tures, in­clud­ing a uni­fied treat­ment of space and time, the in­tro­duc­tion of con­ser­va­tion el­e­ment (CE) and so­lu­tion el­e­ment (SE), and a nov­el shock cap­tur­ing strat­e­gy with­out us­ing a Rie­mann solver. To date, this method has been used to solve many dif­fer­ent types of flow prob­lems, such as det­o­na­tion waves, shock/­acoustic wave in­ter­ac­tion, cav­i­tat­ing flows, and chem­i­cal re­ac­tion flows. In LS-DY­NA, it has been ex­tend­ed to al­so solve flu­id-struc­ture in­ter­ac­tion prob­lems with the em­bed­ded (or im­mersed) bound­ary ap­proach or mov­ing (or fit­ting) mesh ap­proach. For more de­tails, please re­fer to the as­so­ci­at­ed menu links.