The JANNAF 51st2nd 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 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:
Areas of interest included in the Call for Papers are:
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.
Advances in Gun Tube Erosion Analysis and Testing: A majority of the armed services are proposing extended range munitions that can provide battlefield overreach for lethality (range) and terminal effects (velocity). One of the pivotal issues in weapons systems development and maintenance is the material erosion of the gun tube after repeated use – this erosion is caused by both mechanical and chemical processes and is highly dependent on propellant thermo-chemistry. M&S as well as laboratory-scale testing is often used to investigate erosion, but the problem is very complex. We are soliciting technical presentations (presentation required but paper submission is optional) that highlight R&D in gun tube erosion, modeling and simulation as well as lab-scale and simulator testing and propellant characterization. Presentations that address the problem in broad terms as well as those that investigate root causes are equally encouraged. It is planned to solicit the participation of subject matter experts (SMEs) in gun tube erosion from all of the services. The organization of a Gun Tube Erosion Analysis and Testing specialist session will be based on the availability of the SME’s and 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 JDOC 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 considering CB facilities (i.e., pressure range). The relative ease at which SB samples are prepared and data (including visual) is taken considering 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.
Experiment and theoretical studies of solid propellants and their key ingredients are considered in this mission area. These studies can be related to the specific topics listed below.
Specialist Session
Joint EPSS/CS Tutorial on Chemical Kinetics
Chemical Kinetics are fundamental to combustion processes that occur within rocket engines, solid rocket motors, air-breathing missiles, and the exhaust plumes they produce. The correct understanding of chemical kinetic mechanisms is essential to accurately predict and characterize combustion performance, energy release, thrust produced, and observable product species. 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 session is intended to present the recent 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.
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 is 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.
Airbreathing Combustion: Theoretical 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.)
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.
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.
Specialist Session
The Role of Metadata Approaches in the Advancement of Combustion Applications: Experimental chemical kinetics studies in combustion are of foundational importance, wherein discrete findings may be rationalized using modern ab initio quantum chemical, numerical molecular dynamics, or computational fluid dynamics simulations/theories, and/or other approaches to advance combustion models that cover a wide range of conditions. We are interested in metadata approaches that enriches the utilization of such ‘basic’ data, with information, which makes it easier to find, use and manage the entire scope of the relevant data domain, so that rapid advancement and fielding of combustion devices can happen.
In this Specialist Session, any area of the work that pertains to the above description will be considered for presentation.
For questions related to this subcommittee and its mission areas, please contact:
Mr. Peyton Nanney, JHU WSE ERG / Columbia, MD
Telephone: (443) 718-5007
Email: pnanney@erg.jhu.edu