ADVERTISEMENT

Helium Conservation by Diffusion Limited Purging of Liquid Hydrogen Tanks

The NASA Engineering and Safety Center (NESC) has developed an analytical model that predicts diffusion between two gases during piston purging of liquid hydrogen (LH2) tanks. This model helps explain dramatic helium savings seen in a recent Kennedy Space Center (KSC) purge, shows that undesired turbulent mixing occurred in Space...

ISRO’s CE20 Cryogenic Engine Achieves Milestone in Sea-Level Test

The Indian Space Research Organization (ISRO) announced a significant breakthrough in propulsion technology as the CE20 cryogenic engine passed a critical sea-level test, marking a vital step forward for its future space missions. The test, conducted on November 29 at the ISRO Propulsion Complex in Mahendragiri, Tamil Nadu, demonstrated the...

Nottingham Initiates Cryogenic Hydrogen-Electric Flight Program

The University of Nottingham has kicked off a £5.3 million program of research to support the development, manufacture and testing of a revolutionary cryogenic hydrogen-electric propulsion system. The news was announced at the Farnborough International Airshow 2024 and is part of a pioneering £44 million project led by GKN Aerospace,...

A Basic Science Breakthrough

A Yale-led team has found the strongest evidence yet of a novel type of superconducting material, a fundamental science breakthrough that may open the door to coaxing superconductivity — the flow of electric current without a loss of energy — in a new way. The discovery also lends tangible support...

Leon Cooper Dies at 94

Leon Cooper, who has died aged 94, helped to solve a problem that had stumped many of the greatest minds in twentieth-century physics. With his colleagues John Bardeen and Robert Schrieffer, he deciphered the dance of electrons that causes superconductivity, or the sudden drop in electrical resistance experienced by certain materials,...

Korean Scientists Achieve Unprecedented Real-Time Capture of Quantum Information

A research team led by Professor Jaedong Lee from the Department of Chemical Physics at DGIST (President Kunwoo Lee) has unveiled a groundbreaking quantum state and an innovative mechanism for extracting and manipulating quantum information through exciton and Floquet states. Collaborating with Professor Noejung Park from UNIST’s Department of Physics (President Chongrae...

ADVERTISEMENT

Regenerators

Regenerators or regenerative heat exchangers are a key component of cryocoolers such as pulse tube cryocoolers (Cold Facts, August 2014). Regenerator performance greatly affects the coefficient of performance of cryocoolers. Improvements in regenerator design and, in particular, regenerator materials have been an important factor in the improvement of the performance...

Pulse Tube Cryocoolers

The development of pulse tube cryocoolers has been a significant topic of research and development over the past 20 or so years. Pulse tube cryocoolers have a number of advantages over other types of cryocoolers and are now available commercially. In order to understand pulse tube cryocoolers, it’s best to...

Thermal Expansion

Thermal expansion refers to the change in size (length or volume) that a material undergoes as its temperature changes. In cryogenic systems this effect can be quite large and must be allowed for in the design. In isotropic materials, which include most engineering materials, the thermal expansion is the same...

Cryogenic Treatment of Materials

F.J. Diekman Controlled Thermal Processing, Inc. info@metal-wear.com Cryogenic Processing (also called cryogenic treatment, and incorrectly “cryogenic tempering”) is a process that uses cryogenic temperatures to modify materials to enhance their performance. Cryogenic Processing involves the slow reduction in temperature of the material to at least -300°F (-185°C) and holding the...

Cryogenics in Space

Peter Kittel University of California-Berkeley pkittel@cal.berkeley.edu Space Cryogenics is the application of cryogenics to space missions. These applications fall into two broad areas, supporting space science missions and supporting the space transportation infrastructure. Science applications: The atmosphere is opaque to much of the electro-magnetic spectrum. In space, the absence of...

Cryosurgery

Review of Cryosurgery Boris Rubinsky, PhD Hebrew University School of Science and Engineering Research Center for Biomedical Engineering 78b Ross Building Givat Ram, Jerusalem 91904 Israel rubinsky@cs.huji.ac.il as published in Annual Review of Biomedical Engineering, August 2000, Vol. 2, pp. 157-187. Abstract: Cryosurgery is a surgical technique that employs freezing...

Liquefied Natural Gas

Liquefied Natural Gas as it relates to the Field of Cryogenics John W. Bonn VJ Systems, LLC johnbonn@vjsystems-lic.com Today the world is looking for a cleaner fuel and Liquefied Natural Gas (LNG) plays a large part in achieving this goal. LNG in a liquid form is at -162°C (-259°F) and...

An Issue of Pressure and Flow Rate in a Supply Tank

Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...

Using MLI on VJ Line Joints or Cryo Storage Tanks

When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...