Comparative study of turbulence models in application to gas ejectors

An experimental and computational study of the flow pattern in a refrigerant ejector. Validation of turbulence models and real-gas effects

“…The relation of this result to the ejector performance is that the positioning of the shocks should be better captured with the SKE model. This result is in agreement with the PIV study developed by Gagan et al [10] where the shock train structure is better predicted by the SKE model.…”

“…A considerable share of the CFD studies found in the literature, Sriveerakul et al [21], Zhu and Jiang [31], Pianthong et al [36], Zhu et al [37] and Gagan et al [10]; consider the working fluid as an ideal gas. Sometimes, the ideal gas assumption was selected in order to avoid the difficulty in the mathematical model, without verification of it [24].…”

“…The same conclusion was reported Chong et al [7]; who used static wall pressure measurements to validate the CFD model. Gagan et al [10] employed the PIV technique to validate an ejector CFD model and conclude that the best consistency in the flow pattern corresponds to the standard k À ε turbulence model. Thus, there are no clear recommendations regarding the selection of the turbulence model, mainly because the validation is taken as a whole, without a clear distinction between the main mechanism involved in the flow and the mixing of fluids under supersonic conditions in the ejector Thus it is very difficult to recognize the strong and weak points of every model.…”

Ejector refrigeration: A comprehensive review

“…Of particular importance is the dissipative effect of the shock trains as it produces a compression and a shift from supersonic to subsonic conditions. There is considerable research concerning experimental [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] and numerical [66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81] studies of the flow phenomena inside an ejector. Even further detailed knowledge and modeling of these phenomena should allow for better component design.…”

Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

“…In references [69,229], Standard k-ε, Realizable k-ε, RNG k-ε, k-ω SST models were tested with N 2 and air as working fluids, retaining RNG k-ε as the most appropriate for tested conditions. Gagan et al [245] presented flow visualisation investigations by applying the particle image velocimetry (PIV) technique along with CFD modeling and recommended standard k-ε model as best representing their results.…”