 |
| Multi-user Droplet Combustion
Apparatus (MDCA) |
| |
 The
Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user facility
designed to accommodate different droplet combustion science experiments. The
MDCA will conduct experiments using the Combustion Integrated Rack (CIR)
of the NASA Glenn Research Center’s Fluids and Combustion Facility
(FCF). The payload is planned for the International Space Station. The
MDCA, in conjunction with the CIR, will allow for cost effective extended
access to the microgravity environment, not possible on previous space
flights. It is currently in the Engineering Model build phase
with a planned flight launch with CIR in 2007.
The MDCA contains the hardware and software required to conduct unique
droplet combustion experiments in space. It consists of a Chamber
Insert Assembly (CIA), an Avionics Package, and a multiple array of
diagnostics. Its modular approach permits on-orbit changes for
accommodating different fuels, fuel flow rates, soot sampling mechanisms,
and varying droplet support and translation mechanisms to accommodate
multiple investigations. Unique diagnostic measurement capabilities
for each investigation are also provided. Additional hardware
provided by the CIR facility includes the structural support, a combustion
chamber, utilities for the avionics and diagnostic packages, and the
fuel mixing capability for PI specific combustion chamber environments. Common
diagnostics provided by the CIR will also be utilized by the MDCA. Single
combustible fuel droplets of varying sizes, freely deployed or supported
by a tether are planned for study using the MDCA. Such research
supports how liquid-fuel-droplets ignite, spread, and extinguish under
quiescent microgravity conditions. This understanding will help
us develop more efficient energy production and propulsion systems on
Earth and in space, deal better with combustion generated pollution,
and address fire hazards associated with using liquid combustibles on
Earth and inspace.
Flame Extinguishment Experiment (FLEX)
The FLEX experiment was designed to assess and quantify the
effectiveness of inert-gas suppressants in microgravity and obtain
the most conservative estimate of the limiting oxygen index for steady
combustion. FLEX is studying the behavior of near-limit diffusion
flames examining in detail liquid- and gas-phase transport and chemical
kinetics, and developed and is validating detailed and reduced-order
transport and chemistry models that are the foundation for real engine
simulations.
Flame Extinguishment Experiment-2 (FLEX-2)
The second in the FLEX series of experiments, the FLEX-2 investigation
uses fuels and environmental conditions that mimic real combustor
conditions. The investigation will extend and advance the research
into droplet combustion, studying the influence of sub-buoyant convective
flows on combustion rates, determining the influence of a second burning
droplet on a linear array, and beginning the study of practical fuels
by burning bi-component and surrogate fuels. As the research
extends into increasingly complex fuels, FLEX-2 data can help verify
models of real fuels used in transportation and industry. Results
of the FLEX-2 experimental data will help to develop verified detailed
and reduced-order models of droplet combustion, particularly with
flow-field and droplet-droplet interactions.
Flame Extinguishment Experiment-2J (FLEX-2J)
The FLEX-2J experiment is a joint effort between NASA and the
Japanese Space Agency, JAXA, as well as Nihon University and Yamaguchi
University. Derived from the JAXA Group Combustion Experiment
science objectives, the FLEX-2J will complement those goals using
the NASA FLEX-2 hardware and combustion facilities on ISS. FLEX-2J
will observe and measure fuel droplet motions during flame spreading
along a one-dimensional droplet array. Three droplets will be
deployed to fixed positions upon ceramic beads on a silicon carbide
fiber. Then an additional three to ten movable droplets are
positioned to the fiber at known locations. The first fixed
droplet is ignited and the flame is propagated down the array from
droplet to droplet. The subsequent burning and motions of the
unpinned droplets are recorded; particularly the velocities of the
free droplets before and after flame spread are measured. In
addition, the experiment will obtain the history of flame leading
edge position, flame spread limit span, and the growth process of
the group flame along the fuel droplet array. Specifically,
the experiment will measure burning rate, burning time, flame spread
and droplet motion as a function of inter-droplet spacing, ambient
pressure and gas composition.
Flame Extinguishment Experiment Italian Combustion Experiment for Green Air (FLEX-ICE-GA)
The FLEX-Italian Combustion Experiment for Green Air will test
surrogate fuels as defined by the Italian Space Agency (ASI) within
the CIR in the FLEX-2 configuration. A collaborative agreement
between U.S. and Italian scientists from the Italian National Research
Council–Istituto Motori will allow collaboration on research
into biologically derived fuels (bio-fuels) in an investigation into
new, green energy sources. Researchers from the NRC–Istituto
Motori have identified the fuels to be used as 50–50 mixtures
of n-heptane/ethanol and 50–50 n-hexanol/n-decane.
|
| |
| Light Microscope Module
(LMM) |
| |
 The
Light Microscopy Module (LMM) is planned as a remotely controllable
on-orbit microscope subrack facility, allowing flexible scheduling and
control of physical science and biological science experiments within
the GRC Fluids Integrated Rack (FIR) on the International Space Station.
Within the FIR, an initial complement of four fluid physics experiments
will utilize an instrument built around a lightmicroscope. These experiments
are the "Constrained Vapor Bubble" experiment (Peter C. Wayner
of Rensselaer Polytechnic Institute), the "Physics of Hard Spheres
Experiment–2" (Paul M. Chaikin of Princeton University),
the "Physics of Colloids in Space–2" experiment (David
A. Weitz of Harvard University), and the "Low Volume Fraction Entropically
Driven Colloidal Assembly" experiment (Arjun G. Yodh of the University
of Pennsylvania). The first experiment investigates heat conductance
in microgravity as a function of liquid volume and heat flow rate to
determine, in detail, the transport process characteristics in a curved
liquid film. The other three experiments investigate various complementary
aspects of the nucleation, growth, structure, and properties of colloidal
crystals in microgravity and theeffects of micromanipulation upon their
properties. Key diagnostic capabilities include video microscopy to
observe sample features including basic structures and dynamics, thin
film interferometry, laser tweezers for colloidal particle manipulation
and patterning, confocal microscopy to provide enhanced three-dimensional
visualization of colloidal crystal structures, and spectrophotometry
to measure colloidal crystal photonic properties. In addition to using
the confocal system, biological experiments can conduct fluorescence
imaging by using the fiber-coupled output of the Nd:YAG laser operating
at 532-nm, the 437-nm line of a mercury arc, or appropriate narrow-band
filtering of the FIR provided metal halide white light source.
Constrained Vapor Bubble (CVB)
The use of interfacial free energy gradients to control fluid
flow naturally leads to simpler and lighter heat transfer systems because
of the absence of mechanical pumps. Therefore, “passive” engineering
systems based on this principle are ideal candidates for the space program.
In this context, “passive” refers to the natural pressure
field for fluid flow due to changes in the intermolecular force field
under an imposed nonisothermal temperature field. This force field is
a function of the shape, temperature, and composition of the system.
For example, heat pipes which rely on these forces have been proposed
frequently to optimize heat transfer under microgravity conditions.
However, the basic thermophysical principles controlling these systems
are not well understood and, as a result, they have under performed.
In general, the full potential of interfacial forces has not been realized
in transport phenomena.
Therefore, the basic experimental and theoretical studies
of the constrained vapor bubble (CVB) under microgravity conditions
to help remedy this undesirable situation. The proposed use of a transparent
glass cell and related optical measurements will increase the understanding
of transport systems controlled by interfacial phenomena because the
system is viewed directly. Relatively large systems with high heat
fluxes and small capillary pressure levels set in the condenser will
be emphasized.
Pre-Advanced Colloids Experiment-1
(PACE-1)
Pre-Advanced Colloids Experiment-2
/ LMM-Bio (PACE-2/LMM-Bio)
Advanced Colloids Experiment
(ACE)
|
| |
|
|
|
|
| Flammability Assessment
of Materials for Exploration (FLAME) |
|
|
|
| |
|
|
|
|
| |
Two-Phase Flow Separator Experiment
(TPFSE) |
|
|
|
 |
|
|
|
|
|
 |
