Christopher DesAutels
Christopher DesAutels
Managing Scientist
Atmospheric Sciences
  • Maynard

Mr. DesAutels has 15 years of experience conducting air dispersion modeling using EPA guideline models including CALMET/CALPUFF and AERMOD. This experience includes modeling of industrial and mobile sources both in the United States and the Middle East. He has also worked to develop emissions databases and programs for mobile sources to properly account for fleet composition age and vehicle turn over times.

Mr. DesAutels has also conducted Computational Fluid Dynamics (CFD) modeling to understand atmospheric flows and dispersion in complex situations. These have included accidental spills of flashing and dense gases during rail, transportation, and industrial accidents, cooling tower plume re-circulation, building damage from hurricane force wind speeds, and wind energy applications. Mr. DesAutels is experienced in the use of the FLUENT CFD and Star-CCM+ models for atmospheric modeling and has also conducted studies using the OpenFOAM CFD platform. Mr. DesAutels is experienced in system administration and configuration of Linux high power computing systems and programming in both FORTRAN and Perl for manipulating and evaluating large data sets. Mr. DesAutels also has experience with the field operation of SODAR systems and evaluation of collected SODAR data. 

Prior to joining Exponent, Mr. DesAutels was a Senior Meteorologist at TRC Corporations where he conducted air quality and CFD modeling. This work included validation studies of the FLUENT model for accidental large-scale releases of ammonia and H2S. 

CREDENTIALS & PROFESSIONAL HONORS

  • M.S., Geosystems, Massachusetts Institute of Technology (MIT), 2000
  • B.A., Physics, University of Pennsylvania, 1997
  • B.A., Geology, University of Pennsylvania, 1997

Publications

Schulman LL, DesAutels CG, Kolts B. Effectiveness of wind fences to reduce fugitive particulate emissions from material piles: A computational fluid dynamics study. Air & Waste Management Association 106th Annual Meeting, Chicago, IL, June 2013.

Schulman LL, DesAutels CG. Comparing AERMOD and CFD downwash predictions for GEP stacks. Guideline on Air Quality Models: The Path Forward Conference, Raleigh, NC, March 2013.

Ponchaut NF, Kytömaa HK, DesAutels C, Kaganoi S, Becu O, Cardiff G. Modeling of ground flare pits. AIChE Spring Meeting, 12th Topical Conference on Gas Utilization, Houston, TX, April 2012.

Richter RO, Schulman LL, DesAutels CG. Estimating exposure concentrations for trench workers from vapors emanating from soils and groundwater using computational fluid dynamics modeling. Society of Risk Analysis Annual Meeting, San Francisco, CA, 2012.

DesAutels, CG, Schulman, LL. Evaluation of the desert tortoise ammonia field tests with the FLUENT CFD model using unsteady RANS, 5th International Symposium on Wind Engineering, Chapel Hill, NC, 2010.

Schulman LL, DesAutels CG, Viti V. CFD simulations to predict wind induced damage to a steel building during Hurricane Katrina. 5th International Symposium on Computational Wind Engineering, Chapel Hill, NC, May 2010. 

Schulman LL, DesAutels CG. Estimating the effect of building wakes on wind power generation using the CFD model FLUENT. EUEC Energy and Environment Conference, Phoenix, AZ, February 2009. 

Schulman LL, DesAutels CG. CFD simulation of building downwash in the EPA wind tunnel. Air & Waste Management Association 101st Annual Meeting, Portland, OR, June 2008. 

Emanuel K, DesAutels C, Holloway C, Korty R. Environmental control of tropical cyclone intensity. Journal of the Atmospheric Sciences, April 2004. 


Prior Experience

Senior Meteorologist, TRC Corporations, 2006–2011

Meteorologist, Earth Tech, 2000–2005

Senior Associate Engineer, Raytheon, 1997–1999

Project Experience

Wind Damage Modeling – US (2013-2015)
Performed CFD modeling to estimate wind loading on industrial and residential buildings during severe weather events in support of wind damage litigation cases.

CEQA Air Quality Modeling Support – California (2012-2015)
Provided support for an air quality model evaluation of a proposed railyard as part of a California Environmental Quality Act (CEQA) Environmental Impact Report.

Offshore Platform Wind Loading – US (2013-2015)
Performed CFD modeling for off-shore platforms to calculate forces and moments. Compared model results with previously performed wind tunnel studies to validate CFD model performance.

Dust Control Modeling – Ohio (2011-2012)
Performed CFD modeling to evaluate the impacts of wind breaks on dust emissions from coal storage piles at a power plant. Evaluation included simulations of different fence porosities and geometries.

Air Quality Modeling Study – Bahrain (2010-2011)
Performed air emissions inventory tasks to quantify the impacts of both present and future mobile and stationary sources. This included the development of FORTRAN code to track mobile emissions growth, the mobile fleet composition and mobile emission factors over a 30 year period. Performed CALPUFF modeling to predict countrywide impacts and validated the model results against air quality databases. Suggestions were provided to the client on how to minimize future impacts to assist with future planning. CALGRID photochemical modeling was also performed to evaluate local and regional ozone impacts.

H2S Modeling Study – Saudi Arabia (2010) 
Conducted CFD modeling of potential H2S releases at a Gas Oil Separation Plant. Releases included dry evaporation ponds, water filled ponds and venting from storage tanks. The same releases were also evaluated using the dense gas model HGSYSTEMS. Results of different release scenarios were compared to determine risk. 

Petrochemical Modeling – Saudi Arabia (2010). 
Performed CALMET and CALPUFF modeling for a planned expansion at a Saudi Arabian Petrochemical facility. Evaluated the impacts of the plant expansion on ambient SO2, NO2 and PM10 concentrations. Additionally evaluated fugitive dust impacts during the construction phase including development of emission factors. 

Air Quality Modeling Study – Massachusetts (2010) 
Developed a FORTRAN program in order to determine dilution factors for emissions from roadway tunnel portals. The program output will be used to determine emission limits for the roadway tunnels. 

SODAR Deployment and Evaluation – Arizona (2009) 
Field deployed a PA5 SODAR/RASS system in AZ including resolving all technical and infrastructure issues in the field. Evaluated field collected data and coordinated updates and improvements to the SODAR system with the manufacturer. 

CFD Analysis of Cooling Tower Recirculation– Tennessee (2009) 
Mr. DesAutels conducted CFD modeling to help evaluate mitigation strategies to minimize recirculation within an array of cooling towers. Strategies investigated included repositioning towers and physical changes to the tower structures. 

CFD Turbine Siting Study – Massachusetts (2008) 
CFD modeling was performed for winds to aid in the proper siting of roof top wind turbines. Results of the modeling will also be used for educational purposes at the museum. 

CFD Modeling of an Air Cooled Condenser – New Zealand (2008) 
CFD modeling was performed for odor emissions from an air cooled condenser located at a geothermal power plant. CFD modeling was used to validate the proper approach and source term for air dispersion modeling using CALPUFF. 

CFD Modeling of NH3 Releases (2008) 
Conducted multiphase CFD modeling for both aqueous and anhydrous ammonia releases from railcars. These releases included both ground based pools and cold, heavier than air multiphase flows resulting from flashing of released liquids. Discrete phase modeling was used to track both liquid and gaseous phases. Modeled results will be used for transportation planning purposes and risk assessment. 

Wind Turbine Impact Analysis – Massachusetts (2008) 
Conducted CFD modeling in order to quantify the impact of a newly planned library building on a near-by wind turbine. Changes in wind speed and turbulence were analyzed to determine if any adverse effects on energy production should be expected. Analysis guided building redesigns to minimize adverse impacts. 

CFD Modeling of Hurricane Katrina – Louisiana (2008) 
Conducted CFD modeling using the Fluent model to predict building pressures caused by Hurricane Katrina in support of litigation. Modeled winds produced by the MM5 meteorological model were used to initialize the CFD runs. Results demonstrated that pressures caused by the modeled hurricane winds were coincident with observed damage locations, and sufficient to cause the levels of damage observed. 

Mobile Fuel Study – Jeddah, Makkah, and Riyadh, Saudi Arabia (2007) 
Conducted an air quality modeling study, which evaluated the air quality impact of various mobile fuel options for the urban areas around Jeddah, Makkah and Riyadh Saudi Arabia. This study looked both at emission changes due to different fuels, and at the impact that future population growth will have on the urban air quality. Work included the development of a mobile emissions database, modeling using the CALPUFF system, and validation of the modeling results against monitored air quality data. Modeled pollutants included SO2, NOx, PM10, CO and Benzene. 

Regional Air Quality Modeling – Saudi Arabia (2004-2006) 
Mr. DesAutels performed regional modeling studies for both the east coast and west coast of Saudi Arabia. These studies included impacts from both local and long range sources of SO2, NOx and PM10. Modeled sources included power plants, desalination plants, petroleum production facilities, mobile sources and other industrial sources of emissions. 

Power Plant Emission Study – Saudi Arabia (2006) 
Performed air quality modeling of Power Plants at Ghazlan and Qurayyah Saudi Arabia in order to determine the impacts of various fuel use scenarios. These facilities were considered with fuel inputs of natural gas and various types of liquid fuel. Based on the modeling, recommendations were made about how to best operate the facilities, while still staying in compliance with local air quality standards. 

Particulate Modeling Study – Ohio (2006) 
Mr. DesAutels looked at ways to bring a facility in compliance with air quality standards for PM10. CALMET and CALPUFF modeling were conducted to identify problems in the region around the facility. Mr. DesAutels worked closely with the client to develop a detailed solution which met air quality standards, while also taking into consideration the logistical needs of the facility. 

Particulate Modeling Study –Missouri (2004) 
CALPUFF was used to evaluate PM10 emissions sources, including vehicular traffic on haul roads, point source emissions from combustion and volume sources resulting from material handling. 

Cogeneration NOx Study – Saudi Arabia (2004) 
Mr. DesAutels conducted a modeling study which considered the NOx impacts of installing cogeneration equipment at several petroleum facilities in Saudi Arabia. Emission inventories were developed which included the existing facilities, the new cogeneration units, and an estimate of ambient background concentrations based on monitored air quality data. 

Tracer Gas Study – Saudi Arabia (2002) 
Helped to organize and conduct a tracer gas study in Rabigh Saudi Arabia. During this study, SF6 was released from a stack at the Rabigh refinery and samples were taken at locations down-wind. The results of the field study were compared with modeled concentrations predicted by the CALPUFF modeling system. Mr. DesAutels was closely involved with all aspects of the study including study planning, in-field sampling and CALMET/CALPUFF modeling. 


Knowledge

CREDENTIALS & PROFESSIONAL HONORS

  • M.S., Geosystems, Massachusetts Institute of Technology (MIT), 2000
  • B.A., Physics, University of Pennsylvania, 1997
  • B.A., Geology, University of Pennsylvania, 1997