Experiments Support Model Development and Validation
Laboratory Studies at NETL support the development and validation of multiphase flow CFD models. Physical analyses and experiments are performed in the NETL Multiphase Flow Analysis Laboratory (MFAL). MFAL activities are comprised of the following main laboratory programs:
- Particle Characterization Program
- Multiphase Flow Experiment Program
- Advanced Measurement Techniques
- Design and Fabrication
- Particle Dynamics Laboratory
Particle Characterization Program
Key physical properties and fluidization characteristics of the solid phase are important input parameters used in multiphase CFD models. Uncertainty in simulations can be greatly reduced by using accurate information describing individual particle and bulk flow characteristics. These characteristics include particle size, shape, densities, and fluidization properties. The Particle Characterization Program uses standardized methodologies to measure these individual and bulk flow characteristics. Qualitative information is also provided for the materials including bulk photos, photomicrographs, and the assignment of Geldart classifications. The test equipment and methodologies used in the Particle Characterization Program are shown below. The results of the characterization work are captured in NETL’s Granular Material Database and made available to MFS site registered users. The full set of raw and processed data for each granular material in the database is also available for further analysis.
Multiphase Flow Experiment Program
The primary mission of the multiphase flow analysis laboratory is to support the computational fluid dynamics (CFD) modeling efforts at NETL by generating high quality data sets for model development and validation.
To carry out this mission, the laboratory utilizes a range of small-scale test rigs that are designed and fabricated in-house to meet the specifications set by the modeling team. Historically, these small-scale test rigs have included circulating fluidized beds (CFB’s), fluidization test beds used for determination of minimum fluidization velocities, bubbling fluidized beds, chemical looping CFB’s, packed beds, as well as pulsed fluidization and test rigs that are customized for novel diagnostic measurements such as addition of sight windows for inline laser holography measurements of solids circulation rates
Laboratory-scale cold-flow experiments are performed for small-scale, low temperature test units to generate well-characterized, high quality multiphase flow data. The experimental rigs cover a wide range of fixed, moving, bubbling, turbulent, and transport fluidized bed. The materials of construction are selected to allow for visualization of solids and fluid phases and high-resolution measurements using a variety of flow diagnostic techniques such as Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV), Particle Tracking Velocimetry (PTV), and In-line laser holography. These methods, combined with the standard temperature, transient pressure, and gas composition measurements provide a comprehensive data set for model development and validation. These experiments also provide platforms for development of novel measurement techniques.
Periodically, the MFS program conducts formal Multiphase Flow challenge problems.
Advanced Measurement Techniques
The MFAL facility is also focused on developing innovative and advanced techniques and instrumentation for studying multiphase flow. The lab has the following diagnostic capabilities:
- High speed visualization and quantification of multiphase flows.
- Eulerian flow/particle velocity field extraction: Particle Image Velocimetry (PIV)
- Lagrangian flow/particle velocity Particle Tracking Velocimetry (PTV)
- Digital Inline Holography (DIH)
- Machine learning enabled particle image processing
MFAL Design and Fabrication Team
MFAL relies upon a small group of research engineers and scientists to conceptualize, design, fabricate, and operate its research projects. This small group of professionals allow MFAL to quickly respond to its researcher’s needs, as they arise, in a prompt professional manner.
This team is experienced in physical and operational aspects of multiphase flow systems. They also have over 40 years of experience in 3D design and fabrication of traditional piping systems, structural systems, and custom research equipment/systems. This team is able to leverage over 20 years’ experience in 3D printing to design the individual parts in such a way, as to allow the rapid production of these components on our 3D printing systems. Next, they can clean, polish, clear coat, and assemble these 3D print parts to produce the clear flow systems utilized extensively in the MFAL group. The engineers are also experienced in more traditional fabrication methods and techniques including CNC waterjet machining, milling, turning, drilling, tapping, and sheet metal bending. All of this allows MFAL to be a completely self-contained team of expert designers/fabricators who can respond quickly and efficiently to the needs of the research work underway at our facilities.
Particle Dynamics Laboratory (PDL)
The NETL Particle Dynamics Laboratory is used to conduct multiphase flow experiments at larger scales than those typically conducted in the Multiphase Flow Analysis Laboratory. The range of equipment sizes provided in the MFAL and PDL allows for the examination of the effects of scale on multiphase flow hydrodynamics. The PDL laboratory contains numerous examples of different types of common multiphase flow reactor systems, including circulating fluidized beds, spouted beds, and other novel reactor concepts.