Communications of the ACM
Sandia Technologist Looks Back on Bubbles, Balloons, and Beer
Sandia principal technologist Richard Simpson adjusts an igniter assembly at a lake Sandia built to conduct the world's largest liquefied natural gas fire tests ever done on water.
Credit: Randy Montoya / Sandia National Laboratories
Sandia principal technologist Richard Simpson has filled a canyon with soap bubbles, shot photos of flaming liquefied natural gas from a helicopter, floated balloons hundreds of feet in the air to calibrate cameras, chopped out pieces of a Cape Canaveral launch pad to haul across the country for tests, and hoisted a beer with Paul Tibbets, pilot of the B-29 that dropped the first atomic bomb on Japan in World War II.
He also has been audited for buying such things as party bubble juice on his government procurement card.
"You buy 20 party bubble machines, they kind of wonder why. You buy 50 gallons of party bubble juice, and they really wonder why," he says.
Richard Simpson has a pretty interesting job.
Like many of Sandia's technicians and technologists, Simpson has a broad range of technical skills "to where I can contribute in numerous ways to most any project." A Sandian for 27 years, he's been involved in some experiments from conception, design, and fabrication to test and analysis, and in others for only a specific expertise.
There are good days and not-so-good days in field testing, such as freezing one February morning waiting for a test to go off. "There's times when we're digging a trench for instrumentation lines . . . or, oops, this fitting over here leaks, followed by then conducting a once-in-a-lifetime internationally recognized large-scale experiment," he says. "So it goes from totally unglamorous to very exciting and technological."
Over the years, he recalls helping with Sandia's reactor safety experiment programs and rocket propellant fire tests. Last year, it was obtaining slabs of a Cape Canaveral launch pad and nearby asphalt for upcoming studies into how burning rocket propellant impacts surfaces in a launch accident scenario. Because every region uses different aggregate in cement batches, Sandia project leaders wanted concrete from Cape Canaveral to make sure their tests accurately represent the likely fire environment.
Simpson went to Florida where a buddy who worked in the area gave him a name to call. The contact turned out to be the chief of civil engineering at the Cape, and within minutes he had permission to cut up part of a retired launch pad. "Nothing beats starting at the top," Simpson says.
He worked with NASA, the Department of Energy, United Launch Alliance, the Air Force, and others at Sandia and Cape Canaveral to negotiate agreements, set up heavy equipment, complete training, and get final approvals. He found someone to cut 4- by-4-foot by 6-inch slices of concrete from the launch pad and others to package and transport it. He also got samples of asphalt from a road around the complex. "I asked them for permission, 'Can I cut the end of your road off there?'" Simpson says.
The bubble experiments helped improve computer models of jet fuel fire tests.
"Sandia had developed great models of fire, but in a computer model you must have boundary conditions," Simpson says, marking an imaginary boundary with his hands. "You have to tell the computer where to stop its computations; otherwise your fire's going all over here" — waving his hands out of bounds.
But fire is subject to wind, and experts wanted to measure the swirling wind patterns in three dimensions in an area 20-by-20 by 1-foot thick, far larger than a conventional flow visualization field. "We wanted to be at a very large scale, so the engineers thought 'bubbles,'" Simpson says.
He decided to modify something off-the-shelf for Sandia's needs. In this case, that led to a battery of party bubble machines on towers in a canyon where Sandia does burn tests. Then he shone a large spotlight, the kind the Olympics uses to follow ice skaters, into a large spinning mirror he built. The mirror reflected back a foot-thick wall of white light so flow patterns were visible to 3-D cameras shooting the region of interest.
"Stuff was happening way beyond that, which was captured on the wide-view cameras," Simpson says. "We had bubbles all over the canyon."
Tests went off between midnight and 4 a.m. when wind conditions were ideal and the background was black. "So in the middle of the night I'm up there spinning up the large 1,000 rpm mirror, turning on the light, creating this wall of white light, starting up the party bubble machines. . . . Quite a beautiful sight," he says.
Because he's developed specialized camera techniques, much of his work today is macro, time-lapse, and high-speed video. Project engineers call him when they need imagery in a thermally harsh environment, such as documenting experiments in Sandia's solar furnace or weapons component burns. For such situations, he fabricated housings that cool his cameras.
One video shows a test item engulfed in flames. "We actually had a camera in this environment, right down in the bottom of a 1,000-degree Celsius test cell," Simpson says.
He shows off a composite video of another test to study radiant energy and determine the hazard distance around a large natural gas fire on water. He worked with numerous groups to set up imaging, including the Kirtland Air Force Base Special Operations Command, which provided two helicopters to fly photographers and Sandia videographers to document the tests on a pool of water. He also coordinated with Sandia photometrics experts to stage high-definition and high-speed cameras at various points on the ground.
A cold snap froze the pool two nights before the large test, and technicians had to go out in a rowboat to break up the ice. Simpson tried to help by breaking up ice along one edge, taking the opportunity to shoot some video of the technicians power-rowing their craft through an ice field.
Simpson also came up with a way for the photometric team's cameras to measure the height of the flames. "We had to have a calibration image for them," a giant yardstick to scale the camera lenses in advance. Anything higher than 500 feet has to be cleared with the Federal Aviation Administration, so Simpson came up with a 499-foot tethered balloon array with an 8-foot diameter yellow balloon at the top and smaller red balloons attached at 100-foot divisions. "I talked to the [FAA] guy on the phone; he was OK with it. He goes, 'Nope, 499, I don't even want to talk to you,'" Simpson says.
Then there's the beer with Paul Tibbets. Simpson helped when what's now the National Museum of Nuclear Science & History hosted the 509th Composite Group reunion on the 50th anniversary of the 1945 atomic bombing of Hiroshima. Tibbets asked whether Simpson planned to come to the crew's suite for a drink afterward. Simpson remembers his response as "Yes, sir, General." At one point everyone grew quiet while watching television coverage of the anniversary, complete with a classic World War II photo of the crew next to the Enola Gay. "Seeing these guys 50 years ago, and standing next to them, I was just so humbled and honored to be there," Simpson says.
He recalls some griping once during the hard work of setting up a test. "I go, guys, guys . . . later on you're going to look back on it and you're going to say, 'That was pretty cool.' That's it with a lot of the programs. It's rewarding, very rewarding, to know the data that you're producing has national and at times worldwide significance in the scientific and engineering communities."
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