P.Eng., B.A.Sc. (British Columbia), M.Sc., Ph.D. (Cal. Tech.)
Aerosols are liquid or solid particles suspended in a gas. Solid nanoparticles (ie., diameters much less than 1 micron) are produced by combustion processes (eg., diesel engines), and as an atmospheric contaminant, they can have a major impact on climate forcing as well as on human health. It is important to understand the impact of these particles, and more importantly, reduce concentrations of these particles in the indoor and outdoor environments. This overall motivation for my research has taken me and my students down several interconnected paths.
- The first path has been to understand how particle morphology of solid, fractal-like particles (such as soot) affects the transport properties and measurement of the particles. This is an essential component of conducting experimental research on fractal nanoparticles, and an important ingredient in models of particle formation in engines. A related research project has sought to characterize the difference in real particle morphology as a function of engine operating conditions.
- A second path has been the development of new fuel injectors and injection strategies to minimize particle formation in compression ignition engines. This work, done in collaboration with Westport Innovations has been applied and experimental, but my group is working on new phenomenological models of particle formation in engines.
- A third stream of research aims to reduce aerosol concentrations where people spend most of their time – inside buildings. Here the challenge is to remove harmful nanoparticles using filtration systems that do not require excessive energy consumption.
Current Research Work
I am actively pursuing all three research threads above, and interested in bringing new experimental and theoretical techniques to these problems. Graduate student applicants interested in working in these areas should have strong fundamentals in fluid mechanics, heat transfer and a talent for experimental research.
- U. Trivanovic, T.A. Sipkens, M. Kazemimanesh, A. Baldelli, A.M. Jefferson, B.M. Conrad, M.R. Johnson, J.C. Corbin, J.S. Olfert, S.N. Rogak, “Morphology and size of soot from gas flares as a function of fuel and water addition”, Fuel, vol. 279, p. 118478, 2020.
- A. Baldelli, U. Trivanovic, T.A. Sipkens, S.N. Rogak, “On determining soot maturity: A review of the role of microscopy-and spectroscopy-based techniques”, Chemosphere,vol. 252, p. 126532, 2020.
- T.A. Sipkens, J.S. Olfert, S.N. Rogak, “Inversion methods to determine two-dimensional aerosol mass-mobility distributions: A critical comparison of established methods”, Journal of Aerosol Science,vol. 140, p. 105484, 2020.
- A. Baldelli, S.N. Rogak, “Morphology and Raman spectra of aerodynamically classified soot samples”, Atmospheric Measurement Techniques,2019.
- J. Olfert, and S.N. Rogak, “Universal relations between soot effective density and primary particle size for common combustion sources,” Aerosol Science and Technology, pp.1-8, 2019.
- M. Kazemimanesh, R. Dastanpour, A. Baldelli, A. Moallemi, K.A. Thomson, M.A. Jefferson, M.R. Johnson, S.N. Rogak, and J.S. Olfert, “Size, effective density, morphology, and nano-structure of soot particles generated from buoyant turbulent diffusion flames,” Journal of Aerosol Science, 2019.
- A. Baldelli, U. Trivanovic, and S.N. Rogak, “Electron tomography of soot for validation of 2D image processing and observation of new structural features,” Aerosol Science and Technology, pp.1-8, 2019.
- A. Engarnevis, R. Huizing, S. Green, and S.N. Rogak, “Heat and mass transfer modeling in enthalpy exchangers using asymmetric composite membranes,” Journal of Membrane Science, 556, pp.248-262, 2018.
- M. Barimani, S. Green, and S.N. Rogak, “Particulate concentration distribution in centrifugal air classifiers,” Minerals Engineering, 126, pp.44-51, 2018.
- R. Dastanpour, A. Momenimovahed, K. Thomson, J. Olfert, and S. Rogak, “Variation of the optical properties of soot as a function of particle mass,” Carbon, 124, pp.201-211.
- K.K. Leung, E.G. Schnitzler, R. Dastanpour, S.N. Rogak, W. Jäger, and J.S. Olfert, “Relationship between coating-induced soot aggregate restructuring and primary particle number,” Environmental science & technology, 51(15), pp.8376-8383, 2017.
- A. Engarnevis, R. Huizing, S. Green, and S. Rogak, “Particulate fouling assessment in membrane based air-to-air energy exchangers,” Energy and Buildings, 150, pp.477-487, 2017.
- R. Dastanpour, S.N. Rogak, B. Graves, J. Olfert, M.L. Eggersdorfer, and A.M. Boies, “Improved sizing of soot primary particles using mass-mobility measurements,” Aerosol Science and Technology, 50(2), pp.101-109, 2016.
- R. Dastanpour, J.M. Boone, and S.N. Rogak, “Automated primary particle sizing of nanoparticle aggregates by TEM image analysis,” Powder Technology, 295, pp.218-224, 2016.
- R. Dastanpour, and S.N. Rogak, “The effect of primary particle polydispersity on the morphology and mobility diameter of the fractal agglomerates in different flow regimes,” Journal of Aerosol Science, 94, pp.22-32, 2016.
- F. Liu, S.N. Rogak, D.R. Snelling, M. Saffaripour, K.A. Thomson, and G.J. Smallwood, “Effects of laser fluence non-uniformity on ambient-temperature soot measurements using the auto-compensating laser-induced incandescence technique,” Applied Physics B, 122(11), p.286, 2016.
- A. Engarnevis, R. Huizing, A. Vaseghi, S. Green, and S.N. Rogak, “Fouling of Membrane-Based Energy Recovery Ventilators by Aerosols,” In ASHRAE Winter Conference Proceeding (ASHRAE), 2016.
- A. Engarnevis, A. Sylvester, R. Huizing, P. Eng, S. Rogak, and S. Green, “Impact of Environmental Tobacco Smoke on Membrane-Based Energy Recovery Ventilators,” In AAAR 35th Annual Conference, October 2016.
- P. Kheirkhah, P. Kirchen, and S. Rogak, Fast Exhaust Nephelometer (FEN): A New Instrument for Measuring Cycle-Resolved Engine Particulate Emission (No. 2016-01-2329). SAE Technical Paper, 2016.
- B. Graves, J. Olfert, B. Patychuk, R. Dastanpour, and S. Rogak, “Characterization of particulate matter morphology and volatility from a compression-ignition natural-gas direct-injection engine,” Aerosol Science and Technology, 49(8), pp.589-598, 2015.
- T.J. Johnson, J.S. Olfert, J.P. Symonds, M. Johnson, T. Rindlisbacher, J.J. Swanson, A.M. Boies, K. Thomson, G. Smallwood, D. Walters, and Y. Sevcenco, “Effective density and mass-mobility exponent of aircraft turbine particulate matter,” Journal of Propulsion and Power, 31(2), pp.573-582, 2015.
- J.F. Montgomery, C.C. Reynolds, S.N. Rogak, and S.I. Green, “Financial implications of modifications to building filtration systems,” Building and Environment, 85, pp.17-28, 2015.
- A.M. Boies, M.E. Stettler, J.J. Swanson, T.J. Johnson, J.S. Olfert, M. Johnson, M.L. Eggersdorfer, T. Rindlisbacher, J. Wang, K. Thomson, and G. Smallwood, “Particle emission characteristics of a gas turbine with a double annular combustor,” Aerosol Science and Technology, 49(9), pp.842-855, 2015.
- J.F. Montgomery, S.N. Rogak, S.I. Green, Y. You, and A.K. Bertram, “Structural change of aerosol particle aggregates with exposure to elevated relative humidity,” Environmental science & technology, 49(20), pp.12054-12061, 2015.
- J.F. Montgomery, S.I. Green, and S.N. Rogak, “Impact of relative humidity on HVAC filters loaded with hygroscopic and non-hygroscopic particles,” Aerosol Science and Technology, 49(5), pp.322-331, 2014.
- E. Faghani and S. N. Rogak, “A phenomenological model of two circular turbulent jets,” International Journal of Engine Research, vol. 14, no. 3, pp. 293–304, 2013.
- S. H. Park, S. N. Rogak, and A. P. Grieshop, “A Two-Dimensional Laminar Flow Model for Thermodenuders Applied to Vapor Pressure Measurements,” Aerosol Science and Technology, vol. 47, no. 3, pp. 283–293, 2013.
- R. Ghazi, H. Tjong, A. Soewono, S. N. Rogak, and J. S. Olfert, “Mass, mobility, volatility, and morphology of soot particles generated by a McKenna and inverted burner,” Aerosol Science and Technology, vol. 47, no. 4, pp. 395–405, 2013.
- A. Soewono and S. N. Rogak, “Morphology and Optical Properties of Numerically Simulated Soot Aggregates,” Aerosol Science and Technology, vol. 47, no. 3, pp. 267–274, 2013.
- K. Karakama, S. N. Rogak, and A. Alfantazi, “Characterization of the deposition and transport of magnetite particles in supercritical water,” The Journal of Supercritical Fluids, vol. 71, pp. 11–18, 2012.
- S. N. Rogak, W. K. Bushe, and G. McTaggart-Cowan, Concurrent injection of liquid and gaseous fuels in an engine. Google Patents, 2012.
- S. Munshi, G. P. McTaggart-Cowan, S. N. Rogak, and W. K. Bushe, Method and apparatus of fuelling an internal combustion engine with hydrogen and methane. Google Patents, 2012.
- A. P. Grieshop, D. Boland, C. C. Reynolds, B. Gouge, J. S. Apte, S. N. Rogak, and M. Kandlikar, “Modeling air pollutant emissions from Indian auto-rickshaws: Model development and implications for fleet emission rate estimates,” Atmospheric Environment, vol. 50, pp. 148–156, 2012.
- B. Patychuk and S. N. Rogak, “Particulate Matter Emission Characterization From a Natural Gas Fuelled High Pressure Direct Injection Engine,” in ASME 2012 Internal Combustion Engine Division Fall Technical Conference, 2012, pp. 447–455.
- J. F. Montgomery, S. I. Green, S. N. Rogak, and K. Bartlett, “Predicting the energy use and operation cost of HVAC air filters,” Energy and Buildings, vol. 47, pp. 643–650, 2012.