CHEMICAL REACTION RATE EQUATIONS IN NUCLEAR EFFECT CODES

THE PRIMARY TECHNICAL OBJECTIVE OF THE PROPOSED RESEARCH IS TO DEVELOP AN ALGORITHM THAT WILL REMOVE THE STIFFNESS PROBLEM INHERENT IN SETS OF ORDINARY DIFFERENTIAL EQUATIONS FOR THE CHEMICAL KINETICS OF ATMOSPHERIC GASES. THE ALGORITHM SHALL BE SUCH AS TO BE EASILY INCORPORATED INTO A NUCLEAR EFFECTS CODE IN ORDER TO PERMIT IT TO PROVIDE OUTPUTS AT TIMES LATER THAN ARE NOW PRACTICAL IN SOLVING THE CHEMICAL KINETICS EQUATIONS DIRECTLY. ALTHOUGH SEVERAL MATHEMATICAL TECHNIQUES EXIST FOR SOLVING LARGE SETS OF STIFF DIFFERENTIAL EQUATIONS, MORE IS ACCEPTABLE FOR IMPLEMENTATION IN NUCLEAR EFFECTS CODES.THE REASON IS THAT THESE MATHEMATICAL APPROACHES STILL REQUIRE CONSIDERABLE COMPUTER RESOURCES. SINCE THE CHEMICAL KINETICS COMPUTATIONS IN MOST NUCLEAR EFFECTS CODES IS GENERALLY A SMALL PERCENTAGE OF THE TOTAL EFFECTS CALCULATION, THE AMOUNT OF CENTRAL MEMORYF AS WELL AS THE RUNNING TIME ALLOCATED TO THE CHEMISTRY MUST BE MINIMIZED.THIS PROPOSED STUDY SHOULD PRODUCE AN ALGORITHM THAT WILL SATISFY THESE REQUIREMENTS.