Leidenfrost Dusting as a Novel Tool for Dust Mitigation
“Why is cleaning spacesuits on the moon important?”
Lunar dust is an extremely abrasive material that can critically damage and compromise electronics, clothing, and life support systems. In addition, Astronaut Harrison Schmitt and others experienced an ailment they described as “lunar hay fever” from inhalation of lunar dust. Previous removal techniques using brushes, vacuums, and other fluid washes proved ineffective. These methods provided insufficient dust removal and often could damage systems. However, we may have found a solution using the dusting effect of cryogenic liquids.
“How did you notice the dusting effect of cryogenic liquids?”
Sometimes in our … » More …Read Story
Systemic Logistics of a Hydrogen Economy Part 2: The Production Problem
In this multi-part series I’m considering the many logistical challenges of the upcoming hydrogen economy. In Part 1 I considered the people necessary to start and sustain the hydrogen economy. In the subsequent parts/posts I’ll follow the hydrogen through the logistical supply chain to end use. This post is on hydrogen production. Transfer will be Part 3. End use will be Part 4.
Let me be up front that my expertise is hydrogen properties, storage, and distribution (i.e. logistics), and not production. Back in 2005 I saw everyone running into the production and power side (performance minded folks have a tendency towards power) and … » More …Read Story
Systemic Logistics of a Hydrogen Economy Part 1: The People Problem
Welcome 2021 and the World’s new hope for climate salvation: hydrogen.
Since developing the fundamental hydrogen property codes 15 years ago I’ve been waiting for hydrogen to have it’s moment. Despite all of the new press and excitement from folks suddenly interested in hydrogen, I’m here to say that we’re still going to be waiting many more years for hydrogen’s moment to finally arrive. This is evidenced by the many open questions being asked about the future hydrogen economy. We, as a community of stakeholders, still have not addressed many major challenges facing the hydrogen economy. If the ongoing pandemic and struggling vaccine rollout are … » More …Read Story
Could smaller hydrogen liquefiers be better?
This is a pre-print of my October 2020 article for Cold Facts Magazine by the Cryogenic Society of America.
Although the minimum work to liquefy hydrogen is 3.92 kWh/kg, the current best performance for industrial scale hydrogen liquefiers is near 10 kWh/kg. In other words, the best hydrogen liquefiers are only achieving 40% of the theoretically possible efficiency. This energy cost to liquefy hydrogen is approximately 30% the energy content of the fuel at the lower heating value. Given the current trends towards renewable energy and low carbon content of cool electro-fuels like hydrogen, humanity is overdue for fundamental innovations in hydrogen … » More …Read Story
Visualizing density changes with a DSLR Camera
“Tell me what this image is.” I peered closer at the amazing image Jake was showing me. “Displacement?” I guessed nervously, glancing furtively at the inquisitor. “Not quite. Density,” Jake said. This was my interview, to which I had been 15 minutes late and in which I was already sweating profusely. I was in the deep end. Here is the image he showed me:
I was hired to the HYPER Lab despite my blunder, and worked on the Core Team (previously the General Team). By the time this project opportunity surfaced, nearly 6 months had passed since my interview, and the concept of Schlieren … » More …Read Story
Is it parahydrogen or para-hydrogen?
Here’s a paradox of paramount importance: which paradigm is right — parahydrogen or para-hydrogen?
Should a hyphen (-) be used to describe this paranormal spin-isomer of hydrogen with ‘parallel’ nuclear spins?
In this post I’ll review the history of the name, present style guides for the use of a hyphen, and risk ripping the field apart in a debate analogous to the Oxford Comma.
“Astonishing Successes” and “Bitter Disappointment” the history of hydrogen’s specific heat
The discovery of hydrogen’s para- and ortho- nuclear spin isomers was the triumph of Werner Heisenberg’s new quantum theory. So much so that the Nobel Prize committee specifically cited this … » More …Read Story
How to make cryogenic Multi-Layer Insulation (MLI) shields
The Multi-Layer Insulation (MLI) Shield (aka thermal radiation blanket) is very important in cryogenic systems. MLI shields insulate components from thermal energy transferred via light on rockets, satellites, and cryogenic experiments. The shield consists of 10s of alternating layers of polymer mesh and reflective mylar (metalized nylon) film. To understand how MLI blankets work, consider an equation approximating the resistance to radiative heat transfer:
R_rad= 1/(A_s σϵ4(T_s^2+T_sur^2)(T_s^2+T_sur))
where As = radiating surface area, σ = Stefan-Boltzmann constant, ϵ= emissivity, Ts = the absolute surface temperature, Tsur = absolute surroundings temperature. Or more generally: q” = σϵ(T_sur^4-T_s^4) assuming the surface is at lower temperature … » More …Read Story
Orbital TIG Welding – How HYPER strives for the best welds!
Sealing anything at cryogenic temperatures requires extremely tight tolerances. If tight tolerances are not considered, holes may open at the source of the seal, allowing cold leaks to occur as referenced in this past post. In today’s How To, we’re going to discuss how to weld tubes together utilizing orbital TIG welding. Orbital welding has given the lab an advantage in that all our welds minimize human error and the whole operation is computer automated. The system being used is Swagelok’s M200 orbital welding system, which was donated to our lab through the Boeing Cybergrant program. The procedure is as follows:
… » More …Read Story
Cryogenic Hydrogen Embrittlement
There is a reason the HYPER lab is the only academic research lab in the US focused on cryogenic hydrogen: it’s hard.
Recall that hydrogen:
has the largest flammability limits of any gas (4-94% in air by volume).Read Story
has a very low energy barrier for combustion in air (a grain of sand in a jet has enough kinetic energy to ignite).
has the highest combustion energy of any fuel by mass (119.96 MJ/kg).
has one of the lowest boiling points of any fluid (boils near -421°F), highest thermal conductivities, and the highest latent heat (energy required to boil the fluid) per … » More …
Testimony to the WA Senate
I had the wonderful opportunity to present to the WA Senate Transportation sub committee on hydrogen technologies today. The link below includes a ~20 minute video that is a nice primer to what we do and why: