Christopher Choi

Lab website:  Heat and Mass Transfer Laboratory

Program Affiliations

• Biological Systems Engineering

Education and Certificates

• Ph.D. 1990 – Mechanical Engineering, Colorado State University

Fields of Interest

• Heat and Mass Transfer and Computational Fluid Dynamics (CFD)
• Controlled Environments – Livestock Housing & Greenhouse
• Water Distribution System Modeling and Water Quality
• Experimental Methods, Data Acquisition, and Systems Optimization in Biological Systems

Publications

Google Scholar: https://scholar.google.com/citations?hl=en&user=rJwdrgoAAAAJ&view_op=list_works&sortby=pubdate

• Chung H, H Vu, Y Kim, CY Choi (2023), Subcutaneous temperature monitoring through ear tag for heat stress detection in dairy cows, Biosystems Engineering, 235, 202-214.
• Jung S, H Chung, CY Choi (2023), Assessment of Airflow Patterns Induced by a Retractable Baffle to Mitigate Heat Stress in a Large-Scale Mechanically Ventilated Barn, Agriculture, 13 (10), 1910
• Cao M, R Yang, CY Choi, L Rong, G Zhang, K Wang, X Wang (2023), Effects of discharge angle of jet from a slot orifice on cooling performance for a perforated air ducting system in dairy cattle barn, Computers and Electronics in Agriculture, 210, 107890
• Vu H, H Chung, C Choi, Y Kim (2023), ETAG: An Energy-Neutral Ear Tag for Real-Time Body Temperature Monitoring of Dairy Cattle, Mobile Computing and Networking-MobiCom, Proceedings 1-15.
• Zhao W, CY Choi, X Du, H Guan, H Li, Z Shi (2023), Effects of ventilation fans and type of partitions on the airflow speeds of animal Occupied zone and physiological parameters of dairy pre-weaned calves housed individually in a barn, Agriculture, 13 (5), 1002.
• Jung S, H Chung, MR Mondaca, KV Nordlund, CY Choi (2023) Using computational fluid dynamics to develop positive-pressure precision ventilation systems for large-scale dairy houses, Biosystems Engineering. 227, 182-194.
• Kimball BA, K Thorp, E Barnes, CY Choi, et al. (2022) Data from the Arizona (Free-Air CO2 Enrichment) Experiments on Cotton at Ample and Limiting Levels of Water Supply and Nitrogen Fertilization and at various Plant Densities, Open Data Journal for Agricultural Research 8, 1-5.
• Chung H, X Zhang, S Jung, Z Zhang, CY Choi (2022) Application of machine-learned metadata-driven model for dairy barn ventilation simulation, Computers and Electronics in Agriculture, 202, 107350.
• Zhao W, CY Choi, L Ru, Z Shi, L Hao (2022) Effect of rearing systems on growth performance, lying/standing behavior, morbidity, and immunity parameters of pre-weaned dairy calves in a continental zone in winter, Agriculture, 12, 1496.
• Cao M, L Rong, CY Choi, K Wang, X Wang, (2022), Computational evaluation of air jet cooling from a perforated air ducting system to mitigate heat stress of cows in free stalls, Computers and Electronics in Agriculture, 199, 107198.
• Zhao W, CY Choi, G Li, H Li, Z Shi (2021) Pre-weaned dairy calf management practices, morbidity and mortality of bovine respiratory disease and diarrhea, Livestock Science, 251, 104608.
• Zhao W, CY Choi, G Li, L Hao, Z Shi, (2021) Effects of airspeed on the respiratory rate, rectal temperature, and immunity parameters of dairy calves house individually in an axial-fan-ventilated barn, Animals, 11(2), 354.
• Chung H, J Li, Y Kim, JM Van Os, SH Brounts, CY Choi (2020) Using implantable biosensors and wearable scanners to monitor dairy cattle’s core body temperature in real-time, Computers and Electronics in Agriculture, 174, 105453.
• Rojano F, CY Choi, XA Ortiz, RJ Collier (2020) Development of a water pipe network serving as a conductive cooling system applied to dairy farms, Ingeniería Agrícola y Biosistemas, 11(2), 161-179.
• Rojano F, PE Bournet, M Hassouna, P Robin, M Kacira, CY Choi (2019) Modelling the impact of air discharges caused by natural ventilation in a poultry house, Biosystems Engineering 180, 168-181.
• Mondaca MR, CY Choi, NB Cook (2019) Understanding microenvironments within tunnel-ventilated dairy cow freestall facilities: Examination using computational fluid dynamics and experimental validation, Biosystems Engineering, 183, 70-84.
• Zhou B, X Wang, MR Mondaca, L Rong, CY Choi (2019) Assessment of optimal airflow baffle locations and angles in mechanically-ventilated dairy houses using computational fluid dynamics, Computers and Electronics in Agriculture, 165, 1-11.
• Atkins IK, NB Cook, MR Mondaca, CY Choi (2018) Continuous respiration rate measurement of heat-stressed dairy cows and relation to environment, body temperature, and lying time, Transactions of the ASABE, 61(5), 1475-1485.
• Wang X, G Zhang, CY Choi (2018) Evaluation of a precision air-supply system in naturally ventilated freestall dairy barns, Biosystems Engineering, 175, 1-15.
• Rojano F, P Bournet, M Hassouna, P Robin, M Kacira, and CY Choi(2018) Assessment using CFD of the wind direction on the air discharge caused by natural ventilation in a poultry house, Environmental Monitoring and Assessment, 190(12), 724, 1-15.
• Wang X, BS Bjerg, CY Choi, C Zong, G Zhang (2018) A review and quantitative assessment of cattle-related thermal indices, Journal of Thermal Biology, 77, 24-37.
• Drewry JL, M Mondaca, BD Luck, CY Choi (2018) A Computational Fluid Dynamics Model of Biological Heat and Gas Generation in a Dairy Holding Area. Transactions of the ASABE, 61:2, 449-460.
• Wang X, G Zhang, CY Choi (2018) Effect of airflow speed and direction on convective heat transfer of standing and reclining cows, Biosystems Engineering, 167, 87-98.
• Song I, P Romero-Gomez, MA Andrade, M Mondaca, CY Choi (2018) Mixing at junctions in water distribution systems: an experimental study, Urban Water Journal. 15:1, 32-38.
• Holstein AJ, DR Bohnhoff, CY Choi (2018) A computational and experimental study of conjugate heat transfer through composite thermal envelopes in post-frame buildings, Computers and Electronics in Agriculture, 149, 139-149.
• Drewry JL, CY Choi, JM Powell, BD Luck (2018) Computational model of methane and ammonia emissions from dairy barns: development and validation, Computers and Electronics in Agriculture, 149, 80-89.

Other Publications, Book Chapters, and Patents

• Choi CY, KV Nordlund. (2023) US Patent Pending – Positive-Pressure Systems And Methods For Cooling And Ventilation Of Building
• Gerba CP, CY Choi (2009) Chapter 5. Water Quality: The Produce Contamination Problem – Causes and Solutions, Food Science and Technology, International Series, Eds. G Sapers, E Solomon and K R Matthews, Academic Press, San Diego.
• Pepper IL, CY Choi, and CP Gerba (2008) Chapter 28. Microorganisms and Bioterrorism, Environmental Microbiology, Eds. R Maier, IL Pepper, CP Gerba. Academic Press, San Diego.
• Choi CY, NB Cook, KV Nordlund. (2017) US Patent 9706748 – Stall Floor Heat Exchanger reducing Heat Stress and Lameness
• Gerba CP, CY Choi (2006) Role of Irrigation water in Crop Contamination by Viruses, Book Chapter, Viruses in Foods, Eds., S Goyal. Springer, NY, NY.
• Atkins I, Choi CY, Holmes B (2016) Dairy Cooling: Benefits and Strategies.
• Atkins I, Choi CY (2016) Dairy Cooling in Arid and Semi-Arid Climates.
• Atkins I, Choi CY, Holmes, B (2016) Dairy Cooling in Humid Continental Climates.
• Atkins I, Choi CY, Bucklin R (2016) Diary Cooling in Subtropical Climates.

Software Development

AZRED 2.0

Selected Awards and Honors

• Superior Paper Award, A Computational Fluid Dynamics Model of Biological Heat and Gas Generation in a Dairy Holding Area, American Society for Agricultural and Biological Engineers (ASABE), 2019.
• Superior Paper Award, An Evaluation of Simplifying Assumptions in Dairy Cow Computational Fluid Dynamics Models, ASABE International Meeting, American Society for Agricultural and Biological Engineers (ASABE), 2017.
• Superior Paper Award, A conjugate heat and mass transfer model to evaluate the efficiency of conductive cooling for dairy cattle, ASABE International Meeting, American Society for Agricultural and Biological Engineers (ASABE), 2014.
• Superior Paper Award, Analysis of microclimate uniformity in a naturally vented greenhouse with a high-pressure fogging system, ASABE International Meeting, American Society for Agricultural and Biological Engineers (ASABE), 2014.
• Best Paper Award (one out of 106 presented papers), Axial Dispersion in Pressurized Pipe, 10th Annual Water Distribution Systems Analysis Symposium, American Society of Civil Engineers (ASCE), 2008.
• Transactions of the ASABE, Associate Editor
• Computers and Electronics in Agriculture, Guest Editor

Expertise Summary

Dr. Choi’s research interests are in computational and experimental fluid flow and transport phenomena in conjunction with environmental, biological and agricultural engineering applications. His recent research activities have involved: (1) Microclimate simulation and control in livestock buildings, (2) Internet of Things (IoT) and precision agriculture, (3) Optimal design of urban water distribution infrastructures (water safety and security), (4) Microclimate control in greenhouses, (5) Transport and fate of pathogens in fresh vegetables and fruits (food safety), and (6) Computer modeling of algae biofuel production in raceways. He has worked with researchers whose backgrounds are in microbiology, animal sciences, electrical and computer engineering, and civil engineering. He has pursed multi-disciplinary research projects, while maintaining an independent research laboratory for computational simulations and experiments in transport phenomena.