Brian J. Cantwell

Fluid Mechanics, Propulsion, Aerodynamics, Similarity methods

Biographical Sketch

Brian J. Cantwell is the Edward C. Wells Professor Emeritus in the school of engineering at Stanford University. He received the B.A. and B.S. from the University of Notre Dame in 1967 and 1968. Following graduation he worked at the NASA Johnson Space Center where he participated in ground testing of the LEM ascent engine for the Apollo program. In January 1969 he joined the U.S. Army and served on active duty for two years. During military service in Belgium he received the diploma from the Von Karman Institute for Fluid Dynamics. After military service, he attended graduate school at Caltech completing the MS in 1971 and the PhD in 1976. He was a postdoctoral researcher at Caltech from the Fall of 1975 to Fall 1978. He has been a member of the Stanford faculty since 1978 and served as department chairman from 2001 to 2008.

In our research we use theoretical, numerical and experimental methods to investigate the space-time structure of turbulent non-reacting and reacting flows. In the 1980s and early 90s the main emphasis was on the fundamental structure of turbulent bluff-body wakes and the self-similar evolution of the turbulent spot in boundary layer transition. Lie group analysis of the Navier-Stokes and Euler equations was used to study the scaling of free shear flows including jets, wakes and vortex rings. Theoretical and numerical studies of the evolution of three dimensional flow fields led to an improved understanding of the universal structure of turbulent fine scale motions responsible for the dissipation of kinetic energy. This research included, in 1989, one of the earliest uses of Particle Image Velocimetry to measure flow patterns in an unsteady jet flame.

Research in the mid 1990s on the mixing and combustion of a gaseous oxidizer flowing over a solid fuel led to the first identification of a new class of fast burning paraffin-based fuels for hybrid propulsion. The idea of a hybrid thruster is to store the fuel as a solid in the combustion chamber, usually in the form of an annular cylinder with an open channel along its axis called the port. Gaseous oxidizer flowing along the port may originate as a liquid such as liquid oxygen in a storage tank or it might be Air coming from an inlet or a combination of the two. Heating from the diffusion flame over the fuel surface causes the formation of a thin liquid film driven along the surface by the oxidizer flow. For this class of fuels, the viscosity of the liquid is so low that droplets are lifted from the liquid-gas interface producing a fuel spray distributed along the port that substantially increases the overall rate of fuel mass transfer. This feature greatly simplifies propulsion system design and opens up a wide range of applications, especially where high thrust is required.

One oxidizer studied during this period was nitrous oxide which releases energy when it decomposes. This motivated research on N2O as a monopropellant for small space thrusters. As it happens, N2O is also a powerful greenhouse gas and an unwanted byproduct of the nitrification/denitrification process by which ammonia is removed from wastewater. In 2009 our research on nitrous oxide became the basis of a new area of interdisciplinary research in collaboration with faculty in CEE that joins space propulsion and environmental biotechnology. This research produced the first wastewater study where energy is derived from waste nitrogen.

Since 2015 our hybrid propulsion research has been mainly concerned with the problem of solid fuel ignition using methods based on laser heating or the use of materials that spontaneously ignite in the presence of an oxidizer. This has led to the identification of heated particle and heated char based ignition mechanisms and the design of a low cost laser igniter capable of re-igniting a hybrid thruster thousands of times.

In 2018 a re-examination of models of boundary layer combustion used to analyze hybrid thrusters led to a renewed interest in the fundamental structure of non-reacting turbulent boundary layers. An important result of this recent work has been the identification of a new Universal Velocity Profile that accurately approximates pipe and channel flow as well as boundary layer flows with favorable and adverse pressure gradients. The profile is uniformly valid from the wall to the boundary layer edge at all Reynolds numbers. This enables the study of the structure of turbulent wall flows in the limit of infinite Reynolds number while also accurately approximating the velocity profile at low to moderate Reynolds numbers. Recently, this profile was used as the basis of a new method for rapidly and accurately determining the drag of wings and other streamlined bodies over a wide range of Reynolds numbers. Most recently the Universal Velocity Profile has been extended to include wall roughness. Links to open-access papers on the UVP are provided below.

Major professional activities include serving as a member and deputy chairman of the AGARD Fluid Dynamics Panel from 1989 to 1997 supporting the aerospace technology needs of NATO and, from 1994 to 2008, serving as a member of an Executive Independent Review Team overseeing the development of the F119, F135 and F136 engines for the Air Force Raptor and Lighting II fighters.

Teaching accomplishments include the development of courses on aircraft and rocket propulsion, propulsion design, compressible flow, turbulence, similarity methods and experimentation with recognition by the excellence in teaching award from the Stanford student chapter of the AIAA in 1984 and 1988.

Professor Cantwell is a Fellow of the American Physical Society (1996), a Fellow of the AIAA (2003), a Fellow of the Royal Aeronautical Society (2002), a member of Sigma Xi (1976), and a member of the National Academy of Engineering (2004). He is the author of four books including the textbook, "Introduction to Symmetry Analysis", published by Cambridge Press in September 2002 (one of the series, Cambridge Texts in Applied Mathematics). The book is mainly designed for graduate students in science, engineering and applied mathematics although the material is also comprehensible to an upper level undergraduate with a background in differential equations. A link to software for finding the symmetries of ODEs and PDEs is provided below.

Course Materials




Phone/Fax: 650-723-4825 / 650-723-3018
Office: Durand 379