Computational model for predicting the dynamic dissolution and evolution behaviors of gases in liquids

Abstract

Dynamic gas-liquid mass transfer behaviors are widely encountered in the chemical, environmental, and engineering fields. Referring to the Singhal full cavitation model, Henry's law, and Zhou's experiments, we innovatively developed a computational model for dissolved and released mass-transfer to revolutionize the independent unidirectional gas-to-liquid or liquid-to-gas theory. From a new perspective, coupled dissolution and evolution mechanisms were defined similar to how condensation and evaporation were redefined, where dissolution and release mass-transfer prediction methods that can be applied to three-dimensional calculations were integrated for the first time. The dissolved gas saturation concentration was the criterion for determining the direction of mass transfer. According to the theoretical derivation, the driving forces behind the dissolution and evolution are the remaining undissolved gas and real-time solution concentration, respectively. We confirmed the validity of the proposed dynamic model using an unsteady simulation after a grid independence study and an experimental verification of dissolved oxygen concentration in plug-discharge flow. The difference in dissolved oxygen concentration between simulations of this computational model and experiments could be low as 2.0%. A higher dissolved oxygen concentration was distributed in the flow separation and throat gas-liquid blocking zones, indicating that a surge in the flow velocity led to an increased mass transfer rate. In addition, a parametric study was conducted to consider the impact of the oxygen volume fraction and initial dissolved oxygen concentration on the real-time concentration.

Comparisons of oxygen increment in a micropump considering the dissolved and released processes

“…The mass transfer equation of dissolved and released can be expressed as in equation 1, which has been validated in our former derivation [9].…”

“…For the critical criterion , gas eq Y , it is determined by the solute mole fraction ( , gas eq x ) and molar masses of solution and solute ( liq M and gas M ). More details can be referenced from our previous studies [9].…”

Numerical Investigation of Micrometer-Sensitive Particle Intrusion in Hydraulic Valve Clearances and Its Impact on Valve Performance

“…In contrast to the general form of the N-S equation, the physical quantities in the RANS equations are all averaged (including temporal and spatial averages). The RANS equations are as follows [20][21][22][23].…”

Dissolution and evolution effects on pressure fluctuations in a space micropump

“…Therefore, the final mass transfer equation was expressed in equation (12), and detailed parameters information can be referred to in our previous descriptions. 32 When the pressure is higher than p s, there is no free gas and vapor within the solution. When the pressure is less than p s, the dissolved gas begins to separate; the pressure continues to decrease to p v and vaporous cavitation occurs.…”

“…The new dissolved and released gas models were validated and verified using a multiphase plug discharge flow. 32 Within 120 s, the dissolved oxygen concentration (DOC) at M1 increased from 3.38 to 3.56 mg/l, and the (DOC) at M2 increased from 3.57 to 3.80 mg/l, as shown in Figure 5(c). The difference in the DOC between the simulations using this computational model and the experiment results could be as low as 2.0%.…”