The JANNAF 50th Combustion Subcommittee meeting will include sessions on chemical combustion phenomena occurring within the interior of guns and combustors of solid, liquid, and airbreathing (including small or expendable turbojets) missile and space propulsion systems. Papers are solicited that will aid in developing design criteria to build efficient and stable combustion systems. Papers are also invited that will aid in synthesizing, interpreting, and validating current knowledge to make research and development results more useful to design engineers. Specific areas of interest are listed below:

CS Mission Areas

Areas of interest included in the Call for Papers are:

Mission Area I: Ignition and Combustion of Gun Propellants

Dr. Michael J. Nusca, CCDC ARL / Aberdeen Proving Ground, MD
Telephone:  (410) 278-6108

Dr. Eugene Rozumov, CCDC AC / Picatinny Arsenal, NJ
Telephone:  (973) 724-4535

Mr. Michael A. Bonanno, NSWC-IHD / Indian Head, MD
Telephone:  (301) 744-1440

Experimental and modeling studies of ignition, flame spreading, and combustion of solid propellants in guns, mortars and novel gas generators are considered. These studies include the investigation of ignition and ignitability, flame spreading, high-loading density charges, combustion temperature sensitivity, transient combustion (axial and radial pressure waves), and gun barrel erosion under high-pressure gun chamber conditions. Burn rate measurements and techniques, novel gun propelling charge concepts, interior ballistics of grain/stick/disk/consolidated and traveling charges are also considered. Innovative ignition systems and materials, novel chemical igniters and propellant formulations, experimental and analytical techniques to support the production of gun propellants and igniter materials, muzzle flash and blast, mechanical behavior and integrity of propellants in dynamic pressure wave environments, combustion behavior of thermally and mechanically damaged propellant, modeling and studies of surface-coated and deterred propellants, improved gun erosion and ballistic efficiencies through propellant chemical formulations and additive manufacturing are among the many topics included in this mission area. Papers on gun propellant ignition and combustion and propellant vulnerability will be considered for joint CS/PSHS sessions. Technical sessions will be organized as will specialist session that are aimed at discussing new and urgent topics (see below for a list of current topics).

Specialist Sessions

CHEETAH Users Group: As a follow-up to the CHEETAH workshop held at the 48th JANNAF CS Meeting in December 2017, the mission area chairs are soliciting technical presentations (presentation required but paper optional) that highlight applications of the CHEETAH model, observations and/or shortcomings of the model as documented by researchers, and extensions made or suggested to be made to the model for particular applications as performed by individual researchers. The organization of a CHEETAH specialist session will be based on the number of presentations received.

Extended Range Munitions: A majority of the services are proposing extended range munitions that will provide battlefield overreach for lethality (range) and terminal effects (velocity). Soliciting technical presentations (presentation required but paper optional) that highlight requirements for extended range munitions, mission objectives, gun muzzle blast and signature effects, gun propulsion options and post-launch propulsion (rocket motors and ramjets) options. The organization of an Extended Range Munitions specialist session will be based on the number of presentations received.

Gun Propellant Burnrate Determination: As a follow-up to the JANNAF Closed Bomb Round Robin (1982) and subsequent JANNAF Closed Bomb workshops (1998, 2005, 2010) the mission area chairs are soliciting technical presentations (presentation required but paper optional) that highlight new technologies, techniques, and facilities for gun propellant burn rate measurement over a wide range of pressures. Previous JANNAF workshops (reports available from the CPIA database and/or the area chairs) have addressed many of the topics for Closed Bombs (CBs) that require to be updated given new challenges we face in layered, deterred, surface-coated, and additively manufactured gun propellants. In addition, the science of felted–fiber NC combustible cartridge cases has not been fully revealed while at the same time new materials for munition cases such as foamed celluloid are arising. Much of the community is starting to rely upon strand burners (SB) as a replacement for the CB, and so arises the question of SB applicability, confluence, and overlap in light of CB facilities (i.e., pressure range). The relative ease at which SB samples are prepared and data (including visual) is taken in light of pressure range restrictions and/or overlap with CBs is likely to be a popular topic. The organization of a Gun Propellant Burnrate Determination specialist session will be based on the number of presentations received.

Mission Area II: Solid Propellants and Combustion

Dr. Ephraim B. Washburn, NAWCWD / China Lake, CA
Telephone:  (760) 939-0684

  • Decomposition, Ignition, Kinetics, Combustion, and Extinguishment of Ingredients and Solid Rocket Propellants: Decomposition of ingredients and propellants (including kinetics, mechanisms, microstructure, and thermochemistry of thermal decomposition); ignition of ingredients and propellants (including ignition mechanisms, ignition transients, igniter designs, especially smokeless igniters, and new problems associated with ignition); combustion of ingredients and propellants (including burn rate, pressure exponent and temperature sensitivity, understanding the microstructural combustion zone structure, chemistry, and heat release, effect of motor environment, including spin on combustion, transient burning, combustion of fuel rich propellants, analytical modeling including detailed kinetics studies); hazard initiation of propellants (including inadvertent ignition and effects of high burn rate); methods of extinguishing propellants and implementing thrust termination are considered. Of special interest is how these processes are related to new energetic ingredients and how this knowledge may be used to design new propellants that meet more demanding performance, insensitive munitions, and life cycle requirements. (Papers on thermal decomposition ignition and combustion will be considered for joint CS/PSHS sessions.)
  • Failure Analysis of Solid Rocket Motors: Combustion analyses including ignition, flame propagation, burning in cracks and defects, burnback, and flow behavior in support of accident investigations and failure analyses of solid rocket motors are considered. (Papers in this area will be considered for joint CS/PSHS sessions.)
  • Solid Rocket Propellant Combustion Instability: Development, laboratory, and analytical advancements are considered. Specific topics of interest include: combustion response of low smoke propellants; velocity coupled instability; nonlinear instability; instability at high pressures; motor pulsing; mean flow and acoustics interactions; L* instability; high frequency instability in low smoke motors; combustion response function measurement techniques; and analytical methods for predicting propellant response functions and motor stability.
  • Metal Combustion: Behavior of metallic ingredients with special emphasis on nano-particle metals in solid rocket motors is sought. Individual areas of interest include: ignition and burning rate of metal particles or droplets; metal combustion in high density propellants; effects of metal combustion on motor stability and performance; particle phase and size change phenomena; surface melt, agglomeration, and filigree formation; metal combustion in fuel-rich propellants and metal combustion in propellants without ammonium perchlorate; and methods for obtaining in situ particle size measurements.
  • Combustion, Prediction, Performance, and Other Topics in Solid Rocket Motor Behavior: Combustion related motor behavior and the application of analytical models, experimental research, and subscale testing to their solution are considered. Areas of interest include: methodology for standardizing experimental measurements, measurement uncertainties, analytical prediction, computer code verification, correlation, extrapolation, and flight confirmation of performance of solid and liquid rocket, missile and space propulsion systems. Papers on grain design and ballistic modeling are also sought. Behavior in conventional ballistic, tactical, low smoke, controllable, spin-stabilized, ducted, nozzleless motors and gas generators are appropriate subjects for presentation, as are methods for calculating combustion chamber flowfields and their interaction with the motor structural components.
  • Solid Rocket RP-21 Combustion Technologies: Advancements in the understanding of state-of-the-art in combustion technology in solid rocket motors, modeling, and analysis techniques, funded by RP-21 and/or IR&D programs are sought. Advancements in solid propellant combustion are of interest and its impact on selection of case, nozzle, and insulation materials or propellant ingredients. Papers on new or improved methods of thermal, structural, and fluid analysis and improved motor performance prediction and evaluation as related to combustion technology are also solicited.

Joint EPSS/CS Tutorial on Chemical Kinetics
Chemical Kinetics is fundamental to combustion processes that occur within rocket engines, solid rocket motors, air-breathing missiles, and the exhaust plumes they produce. The correct formulation of chemical kinetic mechanisms is essential to the accurate prediction and characterization of combustion performance, energy release, thrust produced, and observable signatures. However, discerning the chemical species, reaction mechanisms, and reaction rates that comprise the kinetic mechanism for a given set of propellant reactants is a complex activity that requires the complementary application of computational chemistry techniques and experimental measurements. This tutorial is intended to present recent the application of computational and experimental methods to determine new or updated chemical kinetic mechanisms of propellants of current interest to the signatures community. The presentations will be made in an open forum format to permit questions during each briefing so as to maximize information exchange and the edification of all attendees.

Mission Area III: Explosive Performance / Enhanced Blast

Dr. Barrie E. Homan, CCDC Army Research Laboratory / Aberdeen Proving Ground, MD
Telephone:  (410) 306-0932

Dr. Eric J. Welle, AFRL / Eglin AFB, FL
Telephone:  (850) 218-4431

Investigations related to detonation and blast performance are sought. Topics ranging from detonation propagation, chemical species formed from the detonation, and combustion processes following the detonation are appropriate for this area. Experimental, theoretical, and computational studies are encouraged that address diverse subjects including; detonation properties, metal driving, enhanced blast, Chem/Bio defeat, target response, underwater blast, and blast protection.

Papers elucidating how new or existing energetic materials and/or novel munitions designs can be exploited are of interest. New experimental techniques, advanced diagnostics and new modeling capabilities that are applicable to the dynamic conditions inherent in detonation events are of interest to this community. Reports of propellant technologies that are applicable to explosive performance are also encouraged.

Of particular interest to this mission area are enhanced blast technologies. Investigations of combustion of detonation products, added fuels, and reactive material dispersal for enhancing blast effects in open-air and various confined structures are sought. Targets of interest include tunnels, caves, multi-room structures, and blast chambers. Papers reporting experimental, theoretical, and computational efforts specifically geared toward understanding the non-ideal, post- detonation energy release phenomena are requested. Papers concerning enhanced blast technologies that exploit novel explosive formulations, non-detonative energetic materials, and munitions designs are of interest.

Specialist Session
High Fidelity Modeling of Reactive Materials: The development of predictive modeling capabilities are required to assess performance and design reactive material (RM) formulations that have the desired chemical and physical properties. Models include continuum mechanics-based predictive code (with input from atomistic and mesoscale submodels) with parameters derived from experimental data obtained from measurements of constitutive behavior as a function of strain, strain rate. The mission area chairs are soliciting technical presentations (presentation required but paper optional) that highlight high fidelity modeling efforts focused on the linkage between mechanical properties and energy release phenomenology of RM. The organization of a Reactive Materials specialist session will be based on the number of presentations received.

Mission Area IV: Airbreathing Combustion

Dr. Mark R. Gruber, AFRL / Wright-Patterson AFB, OH
Telephone:  (937) 255-7350

Airbreathing Combustion: heoretical and experimental investigations of subsonic, supersonic, and hypersonic combustion phenomena for airbreathing systems (including small or expendable turbojet engines) are considered. Specific topics of interest include: analytical and experimental (including CFD) determination of combustor flowfield characteristics; connected-pipe testing, freejet testing, and scaling analyses to free-flight conditions; experiments and analyses relating to ignition, mixing and combustion in liquid-fuel, gel/slurry-fuel, and solid-fuel ramjets, gas generator (ducted rocket) combustors, scramjets, and combined cycle engines; the use of ignition and combustion enhancement techniques; studies of liquid and gel/slurry fuel injection, spray formation, vaporization, and combustion processes; the measurement and analysis of combustion instability phenomena; investigation of the formulation, properties, and combustion of high energy-density single- and multi-phase fuels, including boron and other metal-burning slurries and gels; fundamental investigations of airbreathing combustion. (Papers in this area will be considered for joint CS/APS sessions.)

Mission Area V: Combustion Diagnostics

Dr. Jeffrey S. West, NASA MSFC / Huntsville, AL
Telephone:  (256) 544-6309

This area seeks to bring together the non-intrusive flow field diagnostics and computational fluid dynamics (CFD) communities to create an interaction beneficial to both. Papers are sought from the flow field diagnostics community on the development and implementation of new or existing instrumentation relevant to any combustion problem. Emphasis is placed on methods producing data required for code verification. Similar papers are sought from the computational community emphasizing measurement needs and uncertainties required for verification of existing CFD codes. This interaction is expected to result in development of new instrumentation for combustion research, methods designed specifically for high confidence measurements of critical CFD parameters, and new approaches for creating computational models.

Specialist Session

Enhancing Synergy between Flowfield Diagnostics and Computational Modeling: We envision hosting a specialist session which will focus on the benefits of, and desire for, enhancing synergy between flowfield diagnostics and computational modeling. The relationship between diagnostics and modeling is inherently symbiotic. However, we see a gap in communication between the two communities. Developers of diagnostics need to better understand what modelers require (and to what fidelity) to provide useful data. Modelers need to better understand what flowfield diagnostics can offer currently, and how they might be further developed to provide greater value.

We view participation from both the flowfield diagnostics and modeling communities as key, and therefore anticipate inviting speakers representing both communities and advertising the session to attract the targeted audiences. From a diagnostics perspective, practitioners of non-intrusive on-body and off-body diagnostics would be targeted, but not exclusively. Also, although part of the Combustion Subcommittee, we envision this session representing and attracting diagnosticians and modelers across the broader community including combustion/propulsion, aerodynamics, and structural disciplines.

Mission Area VI: Liquid, Hybrid and Novel Propellants Combustion

Mr. Joel W. Robinson, NASA MSFC / Huntsville, AL
Telephone:  (256) 544-3513

Mr. A. Paul Zuttarelli, AFRL / Edwards AFB, CA
Telephone:  (661) 275-6786

This topic area solicits summaries of work planned, underway, or completed to support state of the art and emerging propellant formulation development for evolving, non-traditional mission applications as well as traditional applications. Primary applications of interest are in aerospace propulsion but would also include primary or auxiliary power system application developments reliant upon rapid gas generation.

  • Combustion Dynamics of Liquid and Gaseous Rocket Propellants: Theoretical and experimental studies of steady and unsteady combustion phenomena in propulsion systems using liquid or gaseous propellants are considered. Areas of interest include: transient system or process analysis; characterization of the physical and chemical processes involved in combustion; performance, heat transfer, and cooling prediction methods for subcomponents, components, and assemblies including CFD approaches; stability prediction models; development and application of new instrumentation techniques applicable to spray characterization and measurement of species characteristics such as type, distribution, temperature, droplet velocity and evolution to vapor, etc.; subsystem effects on stability; feedback control, or other adaptive methods of stabilizing liquid engines; stability rating techniques; and validity of subscale stability studies.
  • Combustion Dynamics of Monopropellant, Bipropellant, and Hybrid Propulsion Systems: Theoretical and experimental studies of steady, unsteady, transition from transient to steady state, and multi-phase combustion phenomena in propulsion systems using liquid monopropellants and bipropellants, liquid oxidizers and solid fuels are considered. Areas of interest include injection, mixing, analytical models of fuel regression rate, chemical kinetics of combustion, ignition system design, and simulation of combustor flows.
  • Combustion Dynamics of Hydrogen Peroxide (HP): Theoretical and experimental studies of combustion phenomena in propulsion systems using HP are considered. Areas of interest include: effect of stabilizers and additives on longevity and reactivity of HP; development of advanced catalysts and catalytic devices for HP decomposition; chemical kinetics of catalysis; direct energy conversion including fuel cells, thermionics, and thermoelectrics; containment strategies mitigating decomposition over time using advanced materials; manufacture and chemical enrichment of HP; and historical usage of HP in propulsion applications.
  • Combustion for Underwater Propulsion: Theoretical and experimental studies, numerical modeling, and simulation of steady and unsteady combustion phenomena in propulsion systems for underwater vehicles are considered. Topics of interest include but are not limited to: experimental determination and numerical simulation of combustor flows; underexpanded reacting jets and their mixing, entrainment, and transport characteristics; transients in combustion processes (e.g., kinetics, ignition, quenching, acoustic oscillations in jets, reverse shocks, coherent turbulent structures in fuel-product baths); experimental studies of non- or slowly-reacting similarity systems; combustion similitude, model development, and verification; radiation and other heat transfer effects; behavior of multiphase and multiple, immiscible liquid-phase constituents in combustors; shock, turbulent mixing, and chemical kinetics interactions; and diagnostic measurements, simulation, and combustion instrumentation for underwater propulsion systems.
  • Areas of specific community interest: Based upon the Combustion Town Hall Meeting held during theDecember 2017 JANNAF Conference, this Mission Area anticipates papers on the following topics: green monopropellant ignition and thruster scaling; MON25 thruster performance and stability; MON30/hybrid performance and stability; density-specific impulse increase of green monopropellants; results from the Air Force Research Laboratory Broad Agency Announcement for green monopropellant thrusters; green hypergolic performance & stability; and multi-mode applications.

Combustion Subcommittee Chair

Dr. Heather F. Hayden, NSWC-IHD / Indian Head, MD
Telephone:  (301) 744-4212

Combustion Subcommittee Deputy Chair

Dr. Ghanshyam L. Vaghjiani, AFRL / Edwards AFB, CA
Telephone:  (661) 275-5657

JHU WSE ERG Technical Representative

Mr. Benjamin Hill-Lam, JHU WSE Energetics Research Group / Columbia, MD
Telephone:  (443) 718-5011