doi:10.1063/5.0062933engDopazo C.Givi P.Ladeinde F.Edward E. O''Brien contributions to reactive-flow turbulenceART-2021-127075Professor Edward Ephraim O''Brien (“Ted”) has made lasting contributions to the theory and modeling of scalar mixing and reaction in turbulent flows. With a doctoral dissertation at The Johns Hopkins University in 1960, entitled “On the Statistical Behavior of a Dilute Reactant in Isotropic Turbulence, ” supervised by the legend Stanley Corrsin, and in the company of notable pioneer of turbulence, John Leask Lumley, Ted''s academic training propelled him through a prolific career. In the opening article of this Special Issue, we provide a review of some of Ted''s contributions. First, a summary is presented of his work on the examination of the failure of the cumulant discard approximation for the scalar mixing. This is followed by a highlight of his impacts on other spectral theories of turbulence including Kraichnan''s direct interaction approximation. His contributions to more modern theoretical/computational description of reactive turbulence are discussed next, including the transported probability density function (pdf) formulation, scalar-gradient pdf transport equation, scalar interfaces, and the filtered density function. Finally, some of his research on Direct Numerical Simulation of compressible turbulence is reviewed. © 2021 Author(s).2021http://zaguan.unizar.es/record/11738110.1063/5.0062933http://zaguan.unizar.es/record/117381oai:zaguan.unizar.es:117381Physics of Fluids 33, 8 (2021), 080403 [12 pp]by-nchttp://creativecommons.org/licenses/by-nc/3.0/es/info:eu-repo/semantics/openAccess