Bibliography

Brenda Kulfan Brenda attended St. Peter and Pauls Catholic Grade School in Grand Rapids Michigan, graduating in 1950. She attended Grand Rapids Catholic Central High School from 1950 to 1954 followed by enrollment in Grand Rapids Junior College. She graduated from the University of Michigan with a Bachelor's degree in Aeronautical Engineering and was admitted to the University of Michigan Masters degree in Aeronautical Engineering. Brenda joined Boeing in 1960.

In 1965, the aerodynamics staff unit contained some very fine supersonic aerodynamicists including Armand Sigalla, Ed Kane, Tom Hallstaff, Wilbur Middleton and Brenda Kulfan. The SST was Boeing's most challenging project and employed many of Boeing's best engineer.

The SST project used a lot of wind tunnel time: low speed, transonic and supersonic. The focus of the supersonic group was to analyze, develop and test supersonic airplane configurations and the group went through many configurations. One of Brenda's tasks was to keep track of how well the group analyses compared to wind tunnel results, make test-theory comparisons, and to develop improved analysis methods. She had multiple notebooks full of such analyses (pre-databases). The computer runs were initiated from IBM punched card decks and the results came back in multiple 11x17 page outputs. Every team member had large stacks of such outputs and Brenda's was especially large.

The unit had 2 principle types of analyses: supersonic wave drag and supersonic wing design and drag-due-to-lift. Both used linear theory which Brenda was and expert in. Linear theory is a wonderful supersonic analysis technique, especially for slender shapes like the SST, but somewhat treacherous in application. Brenda was skilled at judging the quality of the analyses, and was forever acquiring more experience and skill at doing so. Theory was cross-checked with wind tunnel results whenever possible. A saying went "nobody believes the wind tunnel results except the guy who does the work". Brenda spent many years developing her ability to do both jobs.

Brenda was famous for her desire to perform the "holy-grail" of wind tunnel testing, namely, trips only. In supersonic testing (low speed and transonic testing is more complicated), a turbulent boundary layer (to match full scale airplane conditions) is produced over the small scale model configuration by means of grit strip: a strip of tiny carborundum particles near all leading edges. Sizing and placement of the particles is an art, which Brenda was an expert at. Too big particles is overkill and too small is ineffective. The object is to produce transition at the strip from laminar to turbulent boundary layer without incurring significant parasite drag from the strip itself. The group could never tell what was the parasite drag of the strip we were using. Brenda guessed at it which lead to her famous desire to test trips only in the wind tunnel.

The SST died horrible as a major project at Boeing in 1971. It continued as a research project with various levels of emphasis and funding from NASA and Boeing for many more years. Brenda was a principal aerodynamicist and lead engineer in much of that work and developed and international reputation as a supersonic aerodynamicist. With the advent of supercomputers, the analyses performed were much more sophisticated than linear theory and Brenda was a principal engineer in applying them.

- Many thanks to Dan Dierda and Wilbur Middleton