Unlike the other current ACME experiments, the Burning Rate Emulator (BRE) experiment is focused on fire prevention, especially in spacecraft. Specifically, BRE’s objective is to improve our fundamental understanding of materials flammability, such as ignition and extinction behavior, and assess the relevance of existing flammability test methods for low and partial-gravity environments. The burning of … Read the rest ⇢
- The Advanced Combustion via Microgravity Experiments (ACME) project includes five independent experiments investigating laminar gaseous non-premixed flames. In other words, the flow is smooth and without vortices, the fuel is a gas (and not a liquid or solid), and the fuel and oxygen are not mixed in the burner (but are instead on opposite sides of the flame sheet).
- ACME is focused on advanced combustion technology via fundamental microgravity research. The primary goal is to improve efficiency and reduce pollutant emission in practical terrestrial combustion, for example through the development and verification of improved computational models. A secondary objective is fire prevention, especially for spacecraft.
- In addition to enhanced performance, the improved modeling capability resulting from ACME could lead to reductions in the time and cost for combustor design.
- Some specific ACME goals are to improve our understanding of combustion at fuel lean conditions where both optimum performance and low emissions can be achieved, soot control and reduction, oxygen-enriched combustion which could enable practical carbon sequestration, flame stability and extinction limits, and the use of electric fields for combustion control.
- The goal of ACME’s spacecraft fire prevention research is to improve our fundamental understanding of materials flammability, such as extinction behavior and the conditions needed for sustained combustion, and to assess the relevance of existing flammability test methods for the screening and selection of materials for spacecraft.
Research, especially including that already conducted in microgravity, has revealed that our current predictive ability is significantly lacking for flames at the extremes of fuel dilution, namely for sooty pure-fuel flames and dilute flames that are near extinction. The general goal of the Coflow Laminar Diffusion Flame (CLD Flame) experiment is to extend the range … Read the rest ⇢
Electric fields can strongly influence flames because of its effect on the ions present as a result of the combustion reactions. The direct ion transport and the induced ion wind can modify the flame shape, alter the soot or flammability limits, direct heat transfer, and reduce pollutant emission. The purpose of the Electric-Field Effects on … Read the rest ⇢
The primary goal of the Flame Design experiment is to improve our understanding of soot inception and control in order to enable the optimization of oxygen enriched combustion and the “design” of non-premixed flames that are both robust and soot free. An outside review panel recently declared that Flame Design “… could lead to greatly … Read the rest ⇢
The purpose of the Spherical Flame (s-Flame) experiment is to advance our ability to predict the structure and dynamics, including extinction, of both soot-free and sooty flames. The spherical flame, which is only possible in microgravity, will be created through use of a porous spherical burner from which a fuel/inert gas mixture will issue into … Read the rest ⇢
The ACME experiments will be conducted with a single modular set of hardware in the Combustion Integrated Rack (CIR) on the International Space Station (ISS), where the CIR is depicted below. The three main elements of the ACME-unique hardware are the chamber insert (shown below), a high-definition color camera, and an avionics package (for data … Read the rest ⇢