Evaluation of notional nozzle approaches for CFD simulations of free-shear under-expanded hydrogen jets

Free underexpanded jets in a quiescent medium: A review

“…In comparison with the nearfield zone, this region has focused less attention in the past (excluding obviously the ideally expanded jets) however some information may be found concerning the behavior of the jet characteristics since both experimental [30,70,148,39,57,[224][225][226][227][228][229][230][231][232]61,207] and theoretical [28,72,[224][225][226]197,228,[233][234][235][236][237][238][239][240][241]207] and numerical [34,216,230,[242][243][244][245][246][247][248][249]238] papers report thereon. Generally, they deal with risk assessment related to leakage of flammable material (e.g.…”

“…In [230], three nozzles are used to produce H 2 jets releasing in still air. The pressure range is one of the largest ever found for this kind of measurements, since it goes from 52 to 163.…”

“…Axial evolution from[230]: (a) mass fraction and (b) velocity. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)…”

Overview of the DOE hydrogen safety, codes and standards program, part 3: Advances in research and development to enhance the scientific basis for hydrogen regulations, codes and standards

“…Analogous to this approach to predicting the centerline mole fraction decay rate for a momentum-dominated jet by using the effective source diameter and thermodynamic state (density), in the 1-D integral model described earlier that can predict both momentum and buoyancy driven motion, the effective source diameter, thermodynamic state, and velocity are used as boundary conditions. Our current work is focusing on accurately determining the appropriate boundary conditions for input to the plume/jet model, as there is still much ambiguity in the literature regarding this notional nozzle approach [15,18,19].…”

Liquid Hydrogen Release Risk and Behavior Modeling: State-of-the-Art Knowledge Gaps and Research Needs for Refueling Infrastructure Safety.

“…Each model conserves mass [56][57][58], with more complex versions successively considering momentum conservation [59][60][61] and entropy conservation across a normal shock [62] to reduce the number of assumed boundary conditions. Model effectiveness for hydrogen has been evaluated experimentally by Ruggles and Ekoto [50] and numerically by Papanikolaou et al [63], with Ruggles [75] and cryo-compressed hydrogen [76] releases, with the HDE model used as the input boundary condition. However, the results were highly uncertain due to the simplified PHAST models and correlations that have not been validated for relevant hydrogen hazard phenomena (e.g., cold clouds, liquid pools, jet fires or fires, explosions).…”