The JANNAF 14th Liquid Propulsion Subcommittee meeting will include sessions in five general technical areas: liquid engine systems; liquid combustion subsystems and components; liquid propellant feed and pressurization systems; advanced materials for liquid propulsion applications; and rotating detonation rocket engines. Papers are solicited that will aid in the design, development and test of efficient and stable liquid propulsion systems.

LPS Mission Areas

Areas of interest included in the Call for Papers are:

Mission Area I: Liquid Engine Systems

System Models and Data Integration: Analytical tools, system models, and methodologies that support digital engineering throughout the liquid engine lifecycle. Specific interest in analyses or data integration that enable greater comprehension of system interactions and dependencies; Model-Based Engineering (MBE)architectures, design verification and traceability, risk and margin management, test data analysis, and prediction of integrated-system performance, mass, and cost.

Operability, Serviceability, and Reusability: Research associated with rapid operations, maintenance, and increased asset life. Architecture Con-Ops, functional analysis, and designs that improve the efficiency of launch operations or develop a capability for in-space operations.

  • Operability and Serviceability - technologies and designs that increase automation, provide resilient/launch-on-demand capabilities, or enable use over a wider range of launch environments and applications. This can include technologies to address rapid or minimized cleaning/inspection, integrated diagnostics, ability to field remove-and-replace, or approaches to improve launch availability.
  • Modularity - Engine architectures, technologies, and designs that increase the applicability of unique propulsion systems across small, medium and large launch vehicles (scalability), applicability to various mission sets (Commercial launch, Rapid Launch, etc.). Furthermore, approaches to dramatically reduce development timelines and amortize cost by increasing economies of scale of liquid rocket engines.
  • Reusability - Engine designs for high rate flight operations, long in-space missions; 25+ engine firings, refueling operations, system diagnostics, and servicing of critical components.

Liquid Engine Systems for Small Launch Stages & Landers: Design, development, test, and evaluation approaches for liquid propellant rocket engines applicable to small landers and launch vehicle stages: reliability, fabrication, testing, operations, and the affordable integration of those areas. Systems that enable autogenous pressurization, deep throttling capability, cryogenic RCS, or wireless instrumentation and controls are of particular interest. Development strategies that enable integrated stage testing, flight testing, and certification of flight systems are also of interest.

Liquid Engine Systems for Human-Rated Stages & Landers: Design, development, test, and evaluation strategies for liquid propellant rocket engines applicable to human-rated vehicles; including Lunar and Mars landers, Nuclear-Thermal propulsion, commercial space applications, and NASA’s Space Launch System (SLS). Functional requirements and design concepts and/or design modifications for the engines on these vehicles. Advanced methods for fabrication, assembly, and inspections. Plans and programs for conducting integrated stage ground and flight testing. Approaches for meeting government (NASA, FAA, or OCST) safety and reliability requirements for operation with crew and passengers, including fault tolerance, fault detection, isolation, and recovery; crew interaction, reliability predictions and models, and qualification/certification testing requirements and approaches.

Liquid Rocket Engine (LRE) Development History: Papers addressing the important process which LRE have gone through in the course of their development. Particular subjects of note are successes, failures, mishaps, and lessons learned. Topics can be detailed in their information or can provide a general overview of the program. Papers are not limited to flight systems; testbeds, proof-of-concepts, and R & D programs are encouraged as well.

Test Practices, Standards, and Facilities: Industry-consensus best practices and standards for the test and evaluation of liquid engines, components and propulsion/vehicle interaction. Status, capabilities, and operation of government and commercial rocket engine test facilities. This includes training, problem reporting, failure investigation, lessons learned, safety, FOD control, process control, and infrastructure improvements to meet aggressive technical goals. Concepts and innovations for engine life testing, engine fault detection, flight qualification testing practices, data reduction and uncertainty analysis methodologies, and other test needs to meet future demands are of interest.

Mission Area II: Liquid Combustion Subsystems and Components

Thrust Chamber Assembly (TCA) Design and Applications: This mission area addresses the components and subcomponent features required in all sizes of liquid rocket engines. Components include main combustion chambers, preburners, gas generators, nozzles, high temperature nozzles, and their subcomponent features including items such as injectors, stability aids, and coolant passages. Papers on combustion devices are being sought that cover all aspects of design analysis, component test results, test rig development, diagnostic techniques, and novel design features that are being made possible by manufacturing advances.

Hydrocarbon Fuel Properties, Performance, and Specifications and Processes: Papers addressing chemical composition, physical properties, fit-for-purpose quality, cooling and combustion performance, and specification for various hydrocarbon fuels, including RP-1/RP-2, methane, LNG, JP-10 and other high energy density propellants, and alternatively derived fuels (F-T, fIPK, ATJ, etc.); experimental and numerical efforts to characterize operational performance of these fuels in terms of cooling, combustion, and other application-specific processes.

Combustion Stability: Papers addressing design and performance challenges, modeling and simulation techniques, and scaling methods associated with combustion stability in main combustion chambers, preburners, and gas generators for all sizes of liquid rocket engines.

Liquid Injection Systems: The injection system of liquid rocket engines is critical to system performance. This mission area seeks papers describing new injector concepts, the physical processes required to understand injection concepts (including supercritical jets, sprays, and droplets), and methods to determine injector performance and stability.

Modeling and Simulation: Recent advances in modeling and simulation bring forward new capabilities to performance prediction and design of combustion devices. Papers are sought that look at the recent developments, new techniques, results of implementation or comparison with tests. Aspects covered include, but are not limited to: integrated models, injector element dynamics, hot gas flow fields, heat transfer, cooling mechanism, modeling of conventional and novel additively manufactured design features relative to coolant passages, hot wall features, injectors, etc.

Advanced Liquid and Gel Propellants: Papers are sought addressing advanced liquid and gel propellants and the development of supporting technologies such as “green” propellants, fuel management systems and lightweight tankage systems to advance state-of-the-art chemical capabilities.

Hybrid Rocket Engines: Papers addressing hybrid rocket engine systems and the combustion process in these systems.

Mission Area III: Liquid Propellant Feed and Pressurization Systems

Turbomachinery Design and Applications: Turbopump-fed liquid rocket engine systems require the use of high speed and high-performance rotating machinery. Turbomachinery for this application requires support from a wide range of technical disciplines. Technical areas typically considered include the design, analysis, and testing of inducers, impellers, turbines, seals, bearings and structural elements. Papers on liquid rocket engine turbomachinery are being sought that cover all aspects of design, analysis, code development, component test results, test rig development, diagnostics techniques, and system level testing.

Pressurization and Feed Subsystem Design and Applications: This area covers all aspects of design, analysis and testing of the propellant feed system and engine system specific elements. The propellant feed system is composed of tanks, major component lines, pressurization systems, ducts, feed system control valves, and suppression systems. Engine system specific elements include ducts, flow measurement devices and valves. Papers are being sought which address design, analysis, tool development, diagnostics techniques, and testing of propellant feed system elements and engine system specific elements.

Electric Pump Systems: Advances in battery technology and electric motor technology have made it possible to use electric motors to drive propellant pumps. Electric pump systems have applications in rocket engines and propellant feed systems. Papers on electric pump systems are being sought that describe the unique flight system requirements, architecture, and design constraints. Also encompassing all aspects of the pump design, analysis, control system design, component test results, test rig development, diagnostics techniques, and system level testing.

Mission Area IV: Advanced Materials for Liquid Propulsion Applications

Material Applications in Liquid Rocket Engines: Papers are sought addressing advanced materials and processing for liquid rocket propulsion systems, including the following Eight areas:

  1. Material technologies resulting in significant thrust-to-weight ratio increases and/or performance advantages over state-of-the-art capabilities
    • Lightweight, high-temperature nozzle materials
    • Polymer matrix composites (PMCs) for lightweight components and structures
    • PMC resin development for high-temperature or cryogenic environments
    • Materials for lightweight lines, ducts, valves, and tanks
    • Metals, ceramics, and their composites for component applications
    • Materials and production methods for lower lifecycle costs
    • Near net shape production for components and structures
    • Modeling of materials for liquid rocket engines

  2. Materials for Commercial Space Transportation: The recent shift by NASA to commercial space transportation to the ISS under COTS has created the need for low-cost, high performance material solutions for a new generation of space vehicle engines. Papers are sought addressing areas such as:
    • Materials selection criteria
    • Material characterization requirements
    • Flight qualification standards for materials
    • Risk management as related to materials selections

  3. Heavy Lift Launch Vehicles: A need for heavy lift launch vehicles has been identified for future space exploration and other missions. Such a launch vehicle will likely require engines in the 1 million pound thrust class as well as smaller upper stage and other liquid-fueled engines. Papers are sought addressing materials and processes for:
    • Manufacturing and production of new liquid fueled engines
    • Integrated health management for materials and structures
    • Lightweight tanks and composite ducts
    • Materials for reusable engines
    • Concepts for material solutions that optimize the entire propulsion system for improved performance

  4. Nanotechnology for Liquid Propulsion Systems: Application of new nanomaterials to liquid propulsion systems. Papers are sought to address:
    • Nanomaterials and nanoprocessing to improve strength, conductivity, density, modulus, and other properties
    • Concepts of how to integrate nanotechnology into future liquid-fueled rocket engines
    • Nanotechnology areas that may have high payoffs for liquid rocket engine systems

  5. Materials for Green Fuel Engines: New engines with “green” fuels such as methane and ethanol as well as newer fuels that go beyond the traditional definition of green fuels have been proposed. Methods to address the compatibility of these fuels and their combustion products with current and potential future engine materials. Papers are sought to address:
    • Environmental corrosion issues for both the fuels and the combustion products
    • Compatibility test methods
    • Materials concepts for future green fueled engines
    • Concepts for future engines and materials for them

  6. Turbomachinery Materials: Turbomachinery require new materials or coatings to address new engine cycles such as oxygen-rich staged combustion. The chemical and temperature environments will be considerably different than prior expander or gas-generator cycles. Papers are sought to address potential issues such as:
    • Hydrogen and oxygen compatibility
    • Testing for oxygen promoted combustion and hydrogen embrittlement
    • Development process for new materials
    • Criteria for inserting new materials into turbomachinery for hydrogen-, hydrocarbon- and green-fueled engines

  7. Additive Manufacturing: Processing methods using additive manufacturing techniques and other three-dimensional rapid prototyping methods that offer potential for reduction of times to produce parts, cost savings and increased part complexity such as:
    • Selective laser sintering
    • Electron beam sintering
    • UV additive manufacturing
    • Microwave additive manufacturing

  8. Papers are sought for additive manufacturing technologies applied to liquid propulsion applications:
    • Development of techniques
    • Practical examples of application
    • Approaches for Acceptance and Certification for use

Mission Area V: Rotating Detonation Rocket Engines

  • RDRE Thrust Chamber Assembly (TCA) Design and Applications: This mission area addresses the components and subcomponent features required in all sizes of RDREs. RDRE components include main combustion chambers, preburners, gas generators, nozzles, high temperature nozzles, and their subcomponent features including items such as injectors, and coolant passages. Papers are sought on rotating detonation combustion devices including:
    • Unsteady RDRE combustor/nozzle design analysis and simulations for gaseous and multiphase rocket propellants
    • Compatible materials for the unique unsteady supersonic environment
    • Component test results
    • Test rig development
    • Diagnostic techniques and sensors
    • State of the art RDRE modeling simulation techniques for analysis/design of these systems
    • Reduced order modeling approaches for optimizing RDRE performance and design

  • RDRE Test Practices, Standards, and Facilities: Industry-consensus best practices and standards for the test and evaluation of rotating detonation rocket engines, components and propulsion/vehicle interfaces. Papers are sought on the state of the art in RDRE testing, including:
    • Status, capabilities, and operation of government and commercial RDRE test facilities
    • Innovative concepts for RDRE testing, data reduction, and model validation
    • RDRE testing uncertainty analysis methodologies

Mission Area VI: Propulsion-Induced Environments and Structural and Thermal Loads

This area focuses on propulsion-induced environments and the associated loading of a physical structure or material within the surroundings. Fundamentally, an environment represents a source of loading. The source may be a pressure, thermal, thrust, acceleration, or other type of loading. The physical structure may be a launch vehicle, spacecraft, lander, payload, crew, surrounding structure, ground, or other object or material; these are loosely grouped in the summary below as “launch vehicle and surroundings”. While many environments occur during the liftoff phase or landing phase, propulsion-induced environments during the entire mission should not be excluded from this area. The subject area is split into two focus areas, Propulsion-Induced Environments and Structural and Thermal Loads, however this does not exclude many examples where two-way coupling occurs between the source and the structure.

Propulsion-Induced Environments: Modeling, Analysis, Testing, Design, and Validation. Launch vehicles and surroundings are subjected to environments that are induced by propulsion systems. This focus area encompasses the environment and includes analytical and computational tools, models, forcing function definitions, testing, methodologies, validation, physical processes, and mitigation approaches that support propulsion-induced environments.

Examples of propulsion-induced environments are not limited to this list: Liftoff/Landing Acoustics, Engine and Booster Ignition Overpressure, Liftoff Debris Transport, Excess Hydrogen Pop, Thrust Oscillations, Hold-down Acoustics, Engine Nozzle Flow Transient Acoustics, Booster Igniter Shock and Throat Plug Expulsion Overpressure, Infrasonic Acoustics, Far-field Acoustics, Plume Impingement, Plume-Induced Thermal environments, Emissions, Propulsion Noise Sources, Propulsion Blast, and Plume-Surface Interaction.

In general, most of the environments listed above produce a direct pressure, thermal, or acceleration loading and are relatively unambiguous in the environment it produces. Several examples though are not as evident and are described here. Plume-Surface Interaction is an interaction between the environment and the structure but is listed in Propulsion-Induced Environments rather than Structural and Thermal Loads for simplicity. In Plume-Surface Interaction, the plume imparts a pressure, thermal loading, or other environment onto a physical structure or material such as concrete or soil. Physical processes associated with plume-surface interaction could result in pyrolysis and melting, ablation and erosion, and fracture and spalling of material, soil, or regolith. Debris transport and soil particulate impingement to vehicle and surroundings at liftoff and landing can contribute to detrimental loading in the form of impact energy. Emissions or dust can be hazardous to the personnel or to the environment. There are also examples of two-way coupled phenomena such as Slosh and Pogo. In the context of a propulsion-induced environment, a thrust imbalance may contribute to slosh, however the fluid would subsequently impart a pressure on the tank wall relevant to tank design or contribute to a change in mass distribution relevant to vehicle control. And while Pogo is generally recognized as an instability, there are technical aspects and physical processes that fall within this area regarding coupled fluid-structural interaction induced by the propulsion system. Finally, as an example environment mitigation approach, design and analysis activities of the ground system are captured in this area – such as water suppression systems, hydrogen burn-off systems, and appropriate aspects of launchpad design.

Structural and Thermal Loads: Modeling, Analysis, Testing, Design, and Validation. Launch vehicles and surroundings are subjected to environments that are induced by propulsion systems. This focus area encompasses the structural and thermal response to these environments and includes analytical and computational tools, models, testing, methodologies, validation, physical processes, and mitigation approaches that support structural and thermal loads.

Propulsion-induced environments such as dynamic pressure loading is a principal source of structural vibration which may result in the malfunction and fatigue of launch vehicle and surroundings. Pressure loading from the propulsion-induced environments on the external surfaces of a vehicle can damage the vehicle, give rise to sound pressure levels inside a payload cabin which can damage payloads, or inside a crew cabin which may impact the crew's health, safety, or ability to communicate. Other propulsion-induced environments also contribute to stress and failure of vehicle hardware and surroundings.

JHU WSE ERG Technical Representative

Mr. Nicholas Keim, JHU WSE Energetics Research Group / Columbia, MD
Telephone:  (443) 718-5005