Ernest Bert Christiansen, an internationally recognized chemical engineering professor and the former chairman of the chemical engineering department at the University of Utah, died July 9, 1988. He was 77.

Mr. Christiansen was known worldwide for his pioneering research in fluid mechanics and rheology - the study of how matter changes. He was researching the rheology of polymers, synthetic substances made of large molecules, at the time of his death.Mr. Christiansen spent 41 years as a U. faculty member, founding the department of chemical engineering in 1947 and serving as its chairman until 1975. Before joining the U. faculty, he taught at the University of Idaho and spent several years in private industry. He was a design supervisor on the Manhattan District Project that developed the first atomic bomb.

He earned a bachelor of science degree in chemical engineering from the U. in 1937 and master of science and doctorate degrees from the University of Michigan.

He was a fellow of the American Institute of Chemical Engineers and served as national director from 1965 to 1968. He helped found a local chapter of the organization in 1956. Funeral will be Tuesday at 11 a.m. at Wasatch Lawn Mortuary, 3401 Highland Drive. In lieu of flowers, the family suggests donations to the Susan C. Christiansen scholarship fund or the E.B. Christiansen development fund at the U. (See obituary on B15).