In a 50-year career at Los Alamos that began Sept. 1, 1953 as a staff member in the Theoretical Division, until his retirement on Sept. 4, 2003 as a Senior Fellow, Harlow was the inventor of numerous fluid dynamics techniques and came to be known to many associates as the "father of computational fluid dynamics." Harlow, in 1959, became group leader of the then Fluid Dynamics Group; the group was renamed Fluid Dynamics and Solid Mechanics in 2006. He was named a Laboratory Fellow in 1981.

Matthew Maltrud of the Theortical Division said Harlow was his mentor when Maltrud came to Los Alamos in the early 1980s. "He set the course for my professional career because of his mentorship in fluid dynamics," said Maltrud. "He was so engaged in the world, and with students and he was so supportive and easy to work with."

Physicist Len Margolin of Methods and Algorithms Group said Harlow was the first person he met when he came to Los Alamos in 1969. Margolin was watching the Apollo moon landing at his 11th Street apartment. The Harlows lived nearby. "Frank was walking his dog and he stopped by and said 'do you mind if I listen? I don't think I'll make it home in time to watch,' " Margolin recalled. "That was the beginning of my relationship with one of the most creative persons I've ever met."

Harlow also became a leading authority on Pueblo Indian pottery. Earlier this year, Harlow signed copies of a new book he co-authored, "Adventures in Physics and Pueblo Pottery: Memoirs of a Los Alamos Scientist." The book is published by the Museum of New Mexico Press. In the memoir, Harlow describes his life growing up in Washington state, serving in the U.S. Army during World War II, his college years and his career as a physicist at Los Alamos. It was during his relocation to New Mexico that Harlow began studying pueblo pottery. Over the years, Harlow met and interacted with many living pueblo artists, including the famous San Ildefonso Pueblo potter Maria Martinez. Harlow amassed a remarkable collection of Pueblo Indian pottery, which is now in the permanent collection at the Museum of Indian Arts and Culture in Santa Fe.

A U.S. Army veteran, Harlow earned bachelor's and doctoral degrees in physics (minor in mathematics) from the University of Washington.

Harlow is survived by his wife Patricia; daughters, Catherine and Celia; a son Keith; and several grandchildren and great-grandchildren. He was preceded in death by a daughter, Carol.