ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Proving DRACO will deliver
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
Tsutomu Ikeno, Takeo Kajishima
Nuclear Technology | Volume 158 | Number 2 | May 2007 | Pages 249-260
Technical Paper | Nuclear Reactor Thermal Hydraulics | doi.org/10.13182/NT07-A3840
Articles are hosted by Taylor and Francis Online.
A computational model based on a large-eddy simulation (LES) technique was proposed to estimate turbulent mixing and pressure drop in subchannels with grid spacers. For an efficient treatment of this complex geometry, improvements were made to the LES technique coupled with an immersed boundary method: A one-equation dynamic subgrid scale model was introduced to account for the complex geometry without any artificial modification; the higher order accuracy was maintained by a consistent treatment of boundary conditions for velocity and pressure on solid walls. Computations were carried out for each of the convolute and periodic arrangements with two-step inclinations of the mixing vanes. The results reasonably reproduced the geometric effect in the turbulent mixing and drag coefficients for the flow, including unsteady separation and multiple vortices. The present computational model is useful for designing grid spacers: By coarser mesh, one can screen several candidates for spacer design; by finer mesh, more quantitative analysis is possible.