Education

Research Description

Dr. Fang is presently 1) studying engine spray atomization and combustion of liquid fuels, 2) performing fundamental work in understanding liquid break-up in two-phase flows, and 3) investigating liquid droplet interaction with complex surfaces, including fabrics, for Blood Pattern Analysis (BPA) in forensic science applications. Many of his advancements result from his unique strategies for the visualization of the fluid/combustion process. Within MAE, he collaborates with Dr. Buckner, Dr. Edwards, Dr. Ngaile, Dr. Jiang, and Dr. Zhu.

Honors and Awards

• University Faculty Scholar, 2020
• Defense University Research Instrumentation Program (DURIP) Award , 2018
• Ralph R. Teetor Educational Award, SAE International, 2014
• Alcoa Foundation Engineering Research Achievement Award, 2013

Publications

Fundamental study of porcine drip bloodstains on fabrics: Blood droplet impact and wicking dynamics

Wang, F., Gallardo, V., Michielsen, S., & Fang, T. (2021), FORENSIC SCIENCE INTERNATIONAL, 318. https://doi.org/10.1016/j.forsciint.2020.110614

Study of spray structure under flash boiling conditions using 2phase-SLIPI

Du, J., Mohan, B., Sim, J., Fang, T., & Roberts, W. L. (2021), EXPERIMENTS IN FLUIDS, 62(1). https://doi.org/10.1007/s00348-020-03123-1

A comprehensive study of spray and combustion characteristics of a prototype injector for gasoline compression ignition (GCI) application

Du, J., Mohan, B., Sim, J., Fang, T., Chang, J., & Roberts, W. L. (2020), FUEL, 277, 118144. https://doi.org/10.1016/j.fuel.2020.118144

Auto-ignition characteristics of high-reactivity gasoline fuel using a gasoline multi-hole injector

Du, J., Mohan, B., Sim, J., Fang, T., & Roberts, W. L. (2020), EXPERIMENTAL THERMAL AND FLUID SCIENCE, 112. https://doi.org/10.1016/j.expthermflusci.2019.109993

INFLUENCE OF FLASH BOILING ON SPRAY MORPHOLOGY USING A PROTOTYPE INJECTOR FOR GASOLINE COMPRESSION IGNITION (GCI) APPLICATION

Du, J., Mohan, B., Sim, J., Fang, T., Chang, J., & Roberts, W. L. (2020), ATOMIZATION AND SPRAYS, 30(5), 351–369. https://doi.org/10.1615/AtomizSpr.2020034561

Retraction dynamics of water droplets after impacting upon solid surfaces from hydrophilic to superhydrophobic

Wang, F., & Fang, T. (2020), PHYSICAL REVIEW FLUIDS, 5(3). https://doi.org/10.1103/PhysRevFluids.5.033604

Soot characteristics of high-reactivity gasoline under compression-ignition conditions using a gasoline direct injection (GDI) piezoelectric fuel injector

Wang, L., Wu, Z., Badra, J. A., Roberts, W. L., & Fang, T. (2020), FUEL, 265. https://doi.org/10.1016/j.fuel.2019.116931

Study of spray collapse phenomenon at flash boiling conditions using simultaneous front and side view imaging

Du, J., Mohan, B., Sim, J., Fang, T., & Roberts, W. L. (2020), INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 147. https://doi.org/10.1016/j.ijheatmasstransfer.2019.118824

Study of spray structure from non-flash to flash boiling conditions with space-time tomography

Du, J., Zang, G., Mohan, B., Idoughi, R., Sim, J., Fang, T., … Roberts, W. L. (2020), Proceedings of the Combustion Institute. https://doi.org/10.1016/j.proci.2020.06.171

Auto-ignition of direct injection spray of light naphtha, primary reference fuels, gasoline and gasoline surrogate

Wang, L., Wu, Z., Ahmed, A., Badra, J. A., Sarathy, S. M., Roberts, W. L., & Fang, T. (2019), ENERGY, 170, 375–390. https://doi.org/10.1016/j.energy.2018.12.144

View all publications via NC State Libraries

Grants

CDC BAA COVID-19 - Minimal Requirements for Safe and Effective Use of Cloth Masks

Centers for Disease Control & Prevention(12/15/20 - 12/14/22)

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CDC BAA COVID-19 - Minimal Requirements for Safe and Effective Use of Cloth Masks

Sponsor: Centers for Disease Control & Prevention

Start Date: 12/15/20

End Date: 12/14/22

Abstract

Nonwoven fabrics have been used as the optimal technical fabrics for filtration of particles and droplets as they can be effectively engineered and are cheap in production. Normal fabrics, made from knitting or weaving technologies, have not been used as it is harder to create effective filtration media and they would consequently be more expensive. Also their structure is more regular and therefore, in general not as suitable for very high levels (>95%) of filtration of smaller particles, including droplets and liquid aerosols. There has not yet, however, been a controlled study of textile structures, made form yarns into woven and knit fabrics of various types, to explore that principal capabilities and limitations. Regular knit and woven fabrics are created through a hierarchical structure: fibers are blended into yarns and yarns are combined through a structures process, i.e. either knitting which is creating intermingling loops, or wovens creating tightly interlaced yarns. As there are wide ranges of fiber types, yarn structures and knitting and weaving techniques available these days, an almost infinite number of different possibilities (i.e. fabrics) can be created. This makes it impractical to conduct a study on the feasibility of regular (i.e. knit, woven) fabrics to provide filtration efficiency by evaluating currently commercially available fabrics. A systematic approach is needed to vary yarn types and fabric types to assess which basic geometric properties are salient in generating the final fabric performance of high filtration efficiency and generate an empirical model on the predicted filtration level as a function of a limited set of available yarn and fabric structural and geometrical parameters. The benefit of such an approach is that this generated knowledge allows setting of requirements for standards of face masks, for every level of filtration target criteria. It will also facilitate industry in a highly needed way to understand which types of yarns and fabrics may be successful in providing protective functionality. This research project will study the filtration efficiency of a range of fabrics, but a controlled, systematic variation of relevant yarns and fabrics. The yarns and fabrics will be made in house with the available textile production facilities at NC State Universities’ Wilson College of Textiles. Fabric filtration testing will be conducted using the available filtration testing facilities, but will be expanded with high-resolution-high-speed imaging methods to not only measure the numbers if particles in front of and behind the fabrics, but also study the droplet behavior. At various impact speeds, as they are relevant for coughing and sneezing specifically, the larger produced droplets are expelled at higher speeds and initial data suggests that this may lead to breakup of those droplets and consequent aerosolization of smaller droplets, changing the size distribution behind the fabric. As a worst case such fabric behavior would exacerbate the spreading problem instead of providing some protection and this must be addressed. The results of this research will directly contribute to the standards setting organizations in the standards and textile industry (ASTM and AATCC) as well as in the federal government (CDC/NIOSH/NPPTL). Furthermore, as the Wilson College of Textiles is closely related to and actively involved in interactions with US textile producers, the results will directly influence the capability of the US textile industry to produce regular textiles based masks that provide various, but known, levels of filtration of particles of different sizes. This project will fill a crucial knowledge gap to help the US society to produce more and more reliable facemasks without having to revert to ‘trial-and-error.’

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Physical Characteristics of Spatter Stains on Textiles: Influence of Impact Surface Texture, Blood Drop Volume and Blood Drop Velocity

National Institute of Justice(1/01/19 - 6/30/21)

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Physical Characteristics of Spatter Stains on Textiles: Influence of Impact Surface Texture, Blood Drop Volume and Blood Drop Velocity

Sponsor: National Institute of Justice

Start Date: 1/01/19

End Date: 6/30/21

Abstract

Bloodstains are frequently observed at violent crime scenes. These may include stains created from dripping blood, impact of blood with an object, gunshots, and so forth. The analysis of such stains provide valuable information for determining potential methods of creating these stains, which can assist investigators in determining what happened and whether witness statements are consistent with the findings. For many bloodstains, the methods for analyzing them are well documented. However, when the stains occur on textiles, the stains are often altered by the textile itself. When these stains are due to impact spatter, it have proven very difficult to interpret these patterns when found on textiles. This proposal attempts to address this by using fuel injectors with high-speed video to create and track the evolution for single drops impacting onto textile substrates. Subsequent analysis via image processing will characterize the stain evolution on and in the textile substrate.

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MODULAR CONVERSION OF STRANDED ETHANE TO LIQUID FUELS

US Dept. of Energy (DOE) - Energy Efficiency & Renewable Energy (EERE)(1/01/18 - 12/31/21)

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MODULAR CONVERSION OF STRANDED ETHANE TO LIQUID FUELS

Sponsor: US Dept. of Energy (DOE) - Energy Efficiency & Renewable Energy (EERE)

Start Date: 1/01/18

End Date: 12/31/21

Abstract

“Wet” components of shale gas (i.e. hydrocarbons heavier than methane) are imposing new challenges to natural-gas producers and service companies. Ethane, the largest wet component, can represent up to 20 vol. % of shale gas, far exceeding the of 10 vol.% maximum typically allowed for “pipeline-quality” natural gas. Each year, over 210 million barrels (liquid equivalent) of ethane are rejected in the lower 48 states alone. A promising approach to solving this glut is upgrading this low- to negative-value ethane and other natural gas liquids (NGLs) to easily transportable liquid fuels. However, the key to the process economics is development of modular systems that can operate economically at stranded sites. Conventional gas-to-liquids (GTL) technologies face significant challenges in high capital cost and limited energy conversion efficiency, resulting from their complex unit operations including reforming, air separation (for partial oxidation), Fischer-Tropsch (F-T), and product upgrading operations. These challenges can be particularly problematic for small-scale GTL systems. This project aims to demonstrate a fundamentally different modular GTL concept to convert ethane and NGLs to gasoline with 90% capital cost savings and up to 80% reduction in energy demand (for ethane conversion). The proposed modular ethane to liquids (M-ETL) concept uses a modular Chemical-Looping Oxidative Dehydrogenation (CL-ODH) system to convert ethane and NGLs efficiently into olefins (primarily ethylene) via cyclic redox reactions of highly effective oxygen carrier/redox-catalyst particles. The resulting olefins are subsequently converted into synthetic gasoline via oligomerization. The use of advanced reaction and reactive-separation methods eliminates cryogenic air separation and reaction equilibrium limitations (for olefin formation). It also simplifies the process scheme and reduces energy requirements.

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DURIP: Pre-heating Constant Volume Combustion Chamber System for Characterization of Spray Compression-Ignition Combustion

US Dept. of Defense (DOD)(9/14/18 - 6/13/21)

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DURIP: Pre-heating Constant Volume Combustion Chamber System for Characterization of Spray Compression-Ignition Combustion

Sponsor: US Dept. of Defense (DOD)

Start Date: 9/14/18

End Date: 6/13/21

Abstract

A pre-heating constant volume combustion chamber (PHCVCC) system capable of providing compression-ignition conditions similar to the compression-stroke of diesel engines in controlled environments is proposed to be purchased and installed at the Spray and Engine Diagnostics Laboratory (SEDL), Department of Mechanical and Aerospace Engineering of the North Caroline State University. The PHCVCC system is a versatile tool to investigate diesel spray auto-ignition and combustion under high pressure and high temperature environments. The objective of this equipment proposal is to acquire a commercial pre-heating constant volume combustion chamber system, establishing the unprecedented capability at NCSU for extensive characterization of liquid fuel ignition and combustion under precisely controlled environments.

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Supercritical Spray For Dual Fuel Combustion

University Global Partnership Network (UGPN)(8/01/17 - 7/31/18)

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Supercritical Spray For Dual Fuel Combustion

Sponsor: University Global Partnership Network (UGPN)

Start Date: 8/01/17

End Date: 7/31/18

Abstract

This project aims to establish and consolidate a collaboration that allows the researchers from the UPGN partners to conduct a preliminary research on a novel dual-fuel supercritical fuel injection concept. This concept addresses the most important challenge in diesel engine industry and could greatly reduce the diesel engine pollutant emissions, improve the fuel efficiency, and effectively utilize alternative fuels thus reducing overall carbon emissions. The research will be undertaken in a collaborative way by academics with complementary expertise and skills and the tasks include both experimental investigations and numerical modelling.

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Spray Characterization for a Gasoline Direct Injection Fuel Injector

King Abdullah University of Science and Technology (KAUST)(2/16/16 - 8/15/16)

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Spray Characterization for a Gasoline Direct Injection Fuel Injector

Sponsor: King Abdullah University of Science and Technology (KAUST)

Start Date: 2/16/16

End Date: 8/15/16

Abstract

This project is to characterize the spray of a gasoline direct injection (GDI) fuel injector under specified ambient temperature and pressure. The measurements will be conducted in a constant volume spray chamber. Measurements will include high-speed imaging of spray penetration, spray angle, and droplet size under different conditions.

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Use of North Carolina Biomass Resources for Production of Fuels and Materials

NC Biotechnology Center(1/01/16 - 6/30/17)

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Use of North Carolina Biomass Resources for Production of Fuels and Materials

Sponsor: NC Biotechnology Center

Start Date: 1/01/16

End Date: 6/30/17

Abstract

Fast pyrolysis (~500°C, ~1 second, inert environment) is a promising method that can be used to transform lignocellulosic biomass into crude bio-oil, which is potentially compatible in a petroleum refinery. This flexible process has been applied to many types of biomass, including forest resources, agricultural residue, and industrial residue, and used to produce fuels and chemicals. While fast pyrolysis can produce a high bio-oil yield, several challenges remain before the bio-oil can be utilized as a value-added product. The crude bio-oil cannot be used in its original form due to its high acidity, low thermal stability, and high viscosity. For example, bio-oil can polymerize during storage or when heated which causes problems with handling and prevents effective combustion. The reasons for this instability are complex, but these changes are due in part to the presence of highly oxygenated and high molecular-weight compounds. Deoxygenation can be effective for improving stability, and lowering acidity but these processes are expensive and result in a significant loss in yield. Fast pyrolysis of biomass with a high ash content generally lowers the overall yield of bio-oil, but also lowers the oxygen content of the bio-oil, improving its stability. The high ash content biomass also has a lower feedstock cost. The high ash content produces a higher char fraction, which can be used process energy or for materials applications. The solution proposed here is to use commercial diesel oil to ‘extract’ the bio-oil to produce a stand, value-added fraction. The remaining bio-oil fraction can be used as a fuel oil substitute. The char materials can be used for process energy or potentially “activated” to create an activated carbon sorbent material. We will produce bio-oils from common North Carolina feedstocks, which will vary in cost, ash content and biomass composition, and also vary the pyrolysis and extraction conditions to produce a bio-oil blending fuel for diesel engines and direct firing in a furnace. The detail chemistry of various bio-oils will be analyzed by high resolution mass spectrometry (MS) and tandem mass spectrometry (MS/MS) and these chemical details will be correlated with combustion characteristics measured by engine and furnace burner test Criteria for a go/no go decision from a technology perspective includes: • Bio-oil production with w/w yield higher than 60%. • Bio-oil miscibility in diesel for more than 20% • Use of feedstock rich in ash content with low delivered cost • IRR of the investment higher than 12% using historical diesel average prices

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Evaluation of Locomotive Emissions Reduction Strategies

NC Department of Transportation(8/16/15 - 12/31/17)

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Evaluation of Locomotive Emissions Reduction Strategies

Sponsor: NC Department of Transportation

Start Date: 8/16/15

End Date: 12/31/17

Abstract

The key objectives are: (a) to assess baseline fuel use and emission rates (FUER) for prime mover engines (PME) and head end power (HEP) engines for ultra low sulfur diesel (ULSD) fuel; (b) to assess FUER for the newer C15 versus older C18 HEPs to evaluate the effectiveness of Tier 3 (or higher) versus Tier 2 nonroad emission standards; (c) to assess the operational impact of exhaust after treatment systems (EATS) on FUER; (d) to assess the effect of biofuel, and possibly also CNG (depending on availability), on FUER of the newly acquired locomotives; (e) to assess inter-run variability in duty cycles with regard to impact on FUER; and (f) to assess the joint and interactive effect of operational practices, fuels, and EATS on FUER. The key tasks to support these objectives include: (1) development of a detailed study design and preparation for measurements; (2) rail yard (RY) measurements of PMEs and HEPs; (3) over-the-rail (OTR) measurements of PMEs; (4) quantification of the effect of engine technology and EATS on FUER; (5) quantification of the effect of operations; (6) quantification of the effect of fuels; and (7) evaluation of the interactive effect of fuel and emission management strategies and their implications

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Laser Ultrasound Patch Using Carbon Nanofiber Composites

NCSU Research and Innovation Seed Funding Program(7/01/15 - 6/30/16)

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Laser Ultrasound Patch Using Carbon Nanofiber Composites

Sponsor: NCSU Research and Innovation Seed Funding Program

Start Date: 7/01/15

End Date: 6/30/16

Abstract

Unlike the conventional ultrasound transducers with cables, the proposed laser ultrasound is wireless and capable of unprecedentedly remote delivery of ultrasound energy for drug delivery, therapy, and health monitoring of biological and industrial structures. The specific goal of the proposed work is to investigate the carbon nanofiber composites and the associated laser-ultrasound patch (LUP) for ultrasound generation and detections. Specific tasks include: 1) laser ultrasound transduction mechanism study and the LUP transducer design; 2) Fabrication of carbon nanofibers (CNF) with desired optical, thermal and elastic properties and CNF/polymer composite fabrication; 3) CNF characterization, CNF/polymer composite characterization and LUP acoustic characterization; 4) Laser ultrasound tests for drug delivery, thrombolysis, and non-destructive evaluation. This is a truly multidisciplinary research, preliminary data collected under this project will strengthen our future proposals on using laser ultrasound for minimal invasive surgery, drug delivery and wearable electronics to NSF, NIH, DOE and DOD.

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Experimental Validation of Variable Geometry Spray Fuel Injection Technology

Chancellor's Innovation Fund (CIF)(7/01/14 - 12/30/15)

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Experimental Validation of Variable Geometry Spray Fuel Injection Technology

Sponsor: Chancellor's Innovation Fund (CIF)

Start Date: 7/01/14

End Date: 12/30/15

Abstract

American automobiles consume 365.7 million gallons of gasoline per day, and international demand for fuel is increasing at a staggering rate. Although revolutionary technologies are on the horizon, improvements to existing engines have the potential to improve efficiency and reduce emissions now, while providing benefits far into the future. Introducing even modest improvements (5-10%) in the efficiency of internal combustion engines has the potential to save millions of gallons of fuel per day with reduced emissions. One technology with the potential to significantly improve the efficiency of internal combustion engines while simultaneously reducing emissions is variable-geometry spray (VGS) fuel injection. This patent-pending technology enables independent control of fuel flow rate and spray geometry as it enters the combustion chamber. With very limited R&D resources, the investigators have developed three generations of VGS fuel injector prototypes, and preliminary results demonstrate device functionality with low-pressure non-combustible fluids. This VGS injection technology contains novel features which promise improvements over existing injection methods: dual computer-controlled actuators which regulate spray geometry and fuel flow rate independently and continuously throughout the injection process. Due to the uniqueness and commercial potential of this technology, patent applications have been filed through N.C. State’s Office of Technology Transfer (International Application #: PCT/US2009/030707, US Application #: US 2011/0005499 A1). This proposal seeks Chancellor’s Innovation Funding to support the fabrication and testing of VGS fuel injector prototypes in an internal combustion engine to validate the device's performance and enhance opportunities for licensing the technology.

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