ACME: EFIELD - ELECTRIC FIELD EFFECTS ON LAMINAR DIFFUSION FLAMESTHIS PROJECT UTILIZES ELECTRIC FIELDS AND MICROGRAVITY TO ESTABLISH A FUNDAMENTAL UNDERSTANDING OF CHEMI-IONIZATION AND ION-DRIVEN CONVECTION IN FLAMES. IT INTENDS TO USE THIS UNDERSTANDING TO DEMONSTRATE THE ELECTRICAL MANIPULATION OF SOOTING BEHAVIOR AND STABILITY LIMITS IN THE ABSENCE OF BUOYANCY. DETERMINING THESE BEHAVIORS IN MICROGRAVITY CAN THEN LEAD TO ADVANCED APPLICATIONS IN A 1-G ENVIRONMENT. THE RESEARCH IS BASED ON THE FACT THAT ELECTRICAL FORCES ACTING ON CHARGE CARRIERS CREATED THROUGH CHEMI-IONIZATION CAN DETERMINE FLAME CHARACTER AND MANIPULATE FLAME BEHAVIOR. FOR EXAMPLE USING THE DRAG EXERCISED ON FLAME IONS ELECTRIC FIELDS HAVE ALREADY DEMONSTRATED INFLUENCES ON FLAME SHAPE EMISSIONS SOOTING BEHAVIOR BURNING VELOCITY EXTINCTION AND STABILITY. IT HAS BECOME STEADILY CLEAR THAT THE SOURCE OF THESE INFLUENCES RESIDES PREDOMINANTLY IN ION DRIVEN WIND EFFECTS. IN MICROGRAVITY WHERE THERE ARE NO DENSITY-DRIVEN BUOYANT FLOWS TO CONTEND WITH ION WINDS REPRESENT AN IMPORTANT (AND PERHAPS THE ONLY) BODY FORCE THAT CAN BE APPLIED TO MANIPULATE COMBUSTION SYSTEMS INCLUDING THE DIRECTING OF HEAT FLUX TO SURFACES. THIS PROJECT INCLUDES BOTH ACADEMIC STUDY OF ELECTRIC FIELD EFFECTS AND ASPECTS FOR PRACTICAL UTILIZATION OF ELECTRICAL CONTROL OF COMBUSTION PROCESSES. OUR LABORATORY EXPERIMENTS HAVE SHOWN THAT ELECTRICAL PROPERTIES OF FLAMES CAN BE USED TO PRODUCE ENHANCED COMBUSTION PERFORMANCE BY: (A) MANIPULATING FLAME IONS IN ORDER TO CHANGE FLAME CHEMISTRY THIS IS GENERALLY A MINOR INFLUENCE BECAUSE FLAME ION CONCENTRATION IS SMALL BUT IT CAN BE CRITICAL AT NEAR-LIMIT CONDITIONS; (B) CREATING A LOCAL NEUTRAL WIND (ION DRIVEN CONVECTION) THIS PROCESS CAN PROVIDE A LOCAL ACTUATOR FOR FLAME CONVECTION CONTROL; (C) USING ELECTRIC FIELDS TO AFFECT SOOT FORMATION AND TRANSPORT IONS AND SOOT ARE CLOSELY LINKED BECAUSE THERE ARE SHARED CHEMICAL PATHWAYS ALSO SOOT PARTICLES ARE CHARGED BY THE FLAME IONS AND GAIN A NET CHARGE RESULTING FROM A LOW WORK FUNCTION PERMITTING THE RELEASE OF ELECTRONS; AND (D) USING ELECTRICAL PROPERTIES TO CHARACTERIZE FLAMES E.G. THERE IS A RELATIONSHIP BETWEEN FLAME TEMPERATURE THE CARBON CONTENT OF A FUEL THE OXIDIZING ENVIRONMENT AND THE ION CURRENT THAT IS PRODUCED AT SATURATION.IN 1-G THE ABOVE-MENTIONED PROCESSES ARE CONFOUNDED BY COMPLEX BUOYANCY INTERACTIONS THAT CANNOT BE UNRAVELED. HENCE TO EVALUATE THEM IN DETAIL WE HAVE THE FOLLOWING EXPERIMENTAL OBJECTIVES FOR AN EXTENDED MICROGRAVITY ENVIRONMENT: (A) DETERMINE THE RELATIONSHIP BETWEEN ELECTRIC FIELD VOLTAGE AND CHEMI-ION CURRENT AS FUNCTIONS OF TOTAL FUEL FLOW RATE AND THE AMOUNT OF INERT (NITROGEN) IN THE FUEL; (B) COMPARE THE TIME RESPONSE OF THE FLAMES CHEMILUMINESCENCE AND ION CURRENT TO RAPID CHANGES IN ELECTRIC FIELDS; (C) DETERMINE SOOTING BEHAVIOR IN RELATION TO THE ELECTRIC FIELD INFLUENCES; (D) MANIPULATE THE LIMIT BEHAVIOR OF LIFTED FLAMES USING ELECTRIC FIELDS; AND (E) UNDERSTAND THE INFLUENCE OF AN ELECTRIC FIELD ON FLAME BEHAVIOR AND ITS CORRESPONDING CHANGE IN ION PRODUCTION. THE EXPERIMENTAL APPROACH INCLUDES A CO-FLOW BURNER (PRIMARILY RESTRICTED TO 1-G) AND A SIMPLE GAS JET DIFFUSION FLAME WITH PARTICULAR ATTENTION TO THE JET FLAME.THE BASIC VARIATIONS IN THE TESTS ARE IN THE FUEL TYPE (NOMINALLY NON-SOOTING AND SOOTING) AND IN THE LEVEL OF INERT DILUTION OF THE FUEL TO VARY THE FLAME STRENGTH. THE CO-FLOW OR ENVIRONMENT GAS WILL HAVE A NOMINAL MOLAR COMPOSITION OF 21% O2 AND 79% N2. THE EXPERIMENTAL CONCEPT IS TO GROUND THE BURNER TO THE TEST CHAMBER AND TO INSTALL AN ELECTRICALLY ACTIVE PLANAR MESH ELECTRODE DOWNSTREAM OF THE BURNER MOUTH. THE POTENTIAL OF THE MESH ELECTRODE CAN BE EITHER POSITIVE OR NEGATIVE WITH RESPECT TO GROUND WITH A STEADY VOLTAGE OR WITH A TIME VARYING POTENTIAL (INCLUDING A RAPID STEP CHANGE) TO EXAMINE THE FLAMES STEADY STATE RESPONSE AND TIME RESPONSE TO ELECTRIC FIELDS. THE DATA FROM MEASUREMENT