A Tentative Identification of Water Drop Trajectory Investigators

Published: Thu 09 November 2023
Updated: Mon 14 October 2024

tags: impingement

NACA-TN-2094 and investigators operating the water-drop-trajectory analog

Figure 15 of NACA-TN-2904. Water-drop-trajectory analog. Two investigators operate a large mechanical computer. One is seated turning a crank attached to a large cylinder labelled "Input Chart". The second operator turns another input chart crank. Another cylinder is labelled "Droplet Trajectories". There are many shafts and gears visible in the machine. Some machine parts are labelled with the differential equations of motion being solved.
Figure 15 of NACA-TN-2904

Summary

While no one is identified in Figure 15 of NACA-TN-2904, I speculate that these investigators are Helen M. Gallagher, and Dorothea E. Vogt. (I do not know which name goes with which individual). While neither Gallager nor Vogt is credited in NACA-TN-2904, it is possible that they contributed to the analysis, as they did in several other water-drop trajectory publications.

Discussion

Yes, I have used this figure a lot, as it is one of the best of the hundreds I have viewed from the NACA-era. This image is also notable in that of the hundreds of NACA-era documents that I have read, this is the only one where the people appear to be women.

I have not been able to find photos of Gallager or Vogt for comparison (and photos of any NACA-era authors are hard to find). In this photo the individuals are not at good angles for identification anyway.

Women investigators were sometimes named as co-authors of publications. From NASA SP-4306, "Engines and Innovations" 1 [emphasis added]:

The rate of icing on a given surface or shape of a component could then be predicted. The Lewis group extended the available data over a range of airfoil shapes and thicknesses through the use of a differential analyzer. Harry Mergler of the Instrument and Computing Division adapted this early computer designed at MIT by Vannevar Bush to meet the needs of icing research. Although calculating the trajectory of a droplet was still a laborious process, the differential analyzer reduced the time it took for a single calculation from weeks to about four days. Women who had formerly worked the problems on simple mechanical calculators made the transition to the gargantuan differential analyzer with comparative ease. Often they were given the distinction of having their names appear as co-authors of the reports of these studies, no doubt because their contribution went beyond the sheer drudgery of "number crunching." In addition to reducing the time for arduous calculations, the differential analyzer was a potential teacher of higher mathematics. The calculus unfolded mechanically through the gearing and shafts; the chart recorders taught the operators "to grasp the innate meaning of the differential equation." The machine trained them to think in the same logical steps that the machine ground through in making a calculation. Through the back door, women assigned to toil on this giant calculator gained access to the abstruse realm of partial differential equations- a realm in which not all engineers hired during World War II were comfortable.

The rationale for the identification is that Gallager or Vogt collaborated on other publications with Rinaldo Brun as lead author. The publications are before and after NACA-TN-2904.

Selected publications with Brun as lead author:

  • Brun, Rinaldo J., Gallagher, Helen M., and Vogt, Dorothea E.: Impingement of Water Droplets on NACA 651-208 and 651-212 Airfoils at 4° Angle of Attack. NACA-TN-2952, 1953.
  • Brun, Rinaldo J., and Mergler, Harry W.: Impingement of Water Droplets on a Cylinder in an Incompressible Flow Field and Evaluation of Rotating Multicylinder Method for Measurement of Droplet-Size Distribution, Volume-Median Droplet Size, and Liquid-Water Content in Clouds. NACA-TN-2904, 1953.
    > review: NACA-TN-2904
  • Brun, Rinaldo J., Serafini, John S., and Gallagher, Helen M.: Impingement of Cloud Droplets on Aerodynamic Bodies as Affected by Compressibility of Air Flow Around the Body. NACA-TN-2903, 1953.
    > review: NACA-TN-2903
  • Brun, Rinaldo J., Gallagher, Helen M., and Vogt, Dorothea E.: Impingement of Water Droplets on NACA 65A004 Airfoil and Effect of Change in Airfoil Thickness from 12 to 4 Percent at 4° Angle of Attack. NACA-TN-3047, 1953.
  • Brun, Rinaldo J., Gallagher, Helen M., and Vogt, Dorothea E.: Impingement of Water Droplets on NACA 65A004 Airfoil at 8° Angle of Attack. NACA-TN-3155, 1954.
  • Brun, Rinaldo J., and Vogt, Dorothea E.: Impingement of Water Droplets on NACA 65A004 Airfoil at 0° Angle of Attack. NACA-TN-3586, 1955.

I have not found biographies of either investigator. Here are listings from worldcat.org of their publications (the listings on ntrs.nasa.gov are incomplete for these authors).

Hellen Gallager: worldcat.org

Dorthea Vogt: worldcat.org

Update

A relative of Hellen Gallagher confirmed that the woman on the left is her.

S. from Ohio emailed:

The woman on the left is Helen Marie Gallagher (Madden), my Mom. I believe they were doing research for what would become the F-14 fighter.
I found your site while doing a Google search for her - it was a nice surprise to see this photo and your recognition of her and her coworkers. Thank you!
She met my Dad while working at NACA - they got married in 1954. They had eight children together, seven boys and one girl. Helen Marie was an awesome Mom and person.
Thanks again for recognizing her.

An obituary for Helen Marie (nee Gallagher) Madden: obits.cleveland.com

Related

This is part of the Water Drop Impingement on Surfaces thread.

Notes

  1. Dawson, Virginia P. "Engines and Innovation: Lewis Laboratory and American Propulsion Technology. NASA SP-4306." Engines and Innovation: Lewis Laboratory and American Propulsion Technology. NASA SP-4306, by Virginia P. Dawson, 271 pages, published by NASA, Washington, DC, 1991 4306 (1991) ntrs.nasa.gov. ↩

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