AFRL-SR-BL-TR-98- REPORT DOCUMENTATION PAGE OCXo3> - iMriifwfo't "** CGäWO** • ** otQiwiadOw. sow- Kits». , «..a «. W»<u~ mm |»- «"»'«? 3. REPORT TYPE AHO DATES COVERED Final Technical Report 1/15/94-5/31/97 4. TITU AND SUSTJTL1 (U) Application of Parallel Processxng to the Investiga- tion of Supercritical Droplet Evaporation and Combustion Using Molecular Dynamics i. AUTHORtf) Michael M. Micci and Lyle N. Long 7. PERFORMMG ORGANIZATION NAME(S) AND AOOMSSt») Department of Aerospace Engineering The Pennsylvania State University 233 Hammond Bldg. University Park, PA 16802 S. FUN0MG MUM«RS PE - 61102F PR - 2308 SA - BS G - F49620-94-1-0133 ft. PERT ORftNNG ORGANIZATION REPORT NUMOER f. SPOI»SC«G/MONITORING AGENCY NAME(S) AHO ADDftDM»l AFOSR/NA 110 Duncan Avenue, Suite B115 Boiling AFB DC 20332-0001 11. SUPPLEMENTARY NOTES 10. SPONSOPJNG / MONITORING AGENCY REPORT NUMIER 12«. OISTRBUTION/AVAIASRJTY STATEMINT Approved for public release; distribution is unlimited 12k. «STRRÄITION COOE 13. AtSTRAO ißeaaimim200mnrdat Molecular dynamics (MD) implemented on parallel processors was used to model supercritical droplet phenomena occurring in combustion devices. The use of molecular dynamics allows the modeling of supercritical phenomena without an a priori knowledge of the equation of state or transport properties of the individual components or the mixture. Three-dimensional supercritical oxygen vaporization into gaseous oxygen and helium using two-site Lennard-Jones potentials for the oxygen has been modeled and both the disappearance of surface tension above the critical point and the modification of the critical point for a binary mixture have been observed. A distinct change in droplet morphology was observed when passing through its critical point. The droplet remains spherical as it vaporizes under subcritical conditions but becomes broken and cloud-like when supercritical. Equations of state and transport coefficients for mass, momentum and energy have been calculated for supercritical argon, nitrogen and oxygen which agree with NIST values. BEBOP .1 (%> 14. SUaiECT TERNS supercritical, molecular dynamics, droplet vaporization 17* SECURITY OASSffKATON Of REPORT Unclassified NSN 7S4O-01-MO-5500 1 'it. SECURITY OASSffKAÜÖN Of TMS PAGE Unclassified 1«. SSCUMTY OASStftCATION (M> ABSTRACT Unclassified IS. NUMIER OT 'AGES 12 ItPRKICOOE 20. UNRTATION 0» ARSTRÄCT UL Standard Form 290 (890104 On« UM«