Numerical investigation of flow boiling in manifold microchannel-based heat exchangers

Development of Methods for Heat Transfer Enhancement During Nitrogen Boiling to Ensure Stabilization of HTS Devices

“…Significant demand for energy-intense heat exchangers for electronic devices has been observed in recent decades [36][37][38][39][40]. An important direction in increasing the efficiency of phase-transition cooling systems is application of coatings to change properties of surfaces on which the phase transition occurs [41][42][43], creation of a special geometry [44][45][46][47][48][49], and formation of micro-and nanoscale structures [50][51][52][53][54].…”

Efficient Mesh Interface Engineering: Insights from Bubble Dynamics in Electrocatalysis

“…Gas bubbles start to nucleate at the electrode surface as the concentration of dissolved gas molecules increases to make the electrolytic solution become supersaturated and the small gas clusters overcome the activation barrier to form the nuclei. , Gas bubbles continue growing until they detach from the electrode surface. The dynamics of bubble growth at the solid surface has been extensively studied in the gas-evolving electrochemical reaction and boiling heat transfer. ,− Two growth patterns and related parameters such as liquid density and supersaturation (superheat) have been proposed and confirmed in numerical and experimental investigations. ,, It is found that the growth of bubbles can induce local convective flows near the gas–liquid interface and enhance mass transport. As bubbles detach from the electrode, they will also generate a transient turbulent wake that greatly enhance the local mixing of the species and decreases the concentration gradients near the trajectory, which bolsters the local mass and energy transport process and increases system efficiency. ,, However, on the other hand, growing bubble reduces the reaction area of the electrode surface and hinders the chemical reaction. ,, Practically, the most effective strategy to resolve this dilemma perhaps is to reduce the growth time and accelerate the detachment of the gas bubble at the electrode surface, which usually promotes bubble departure by applying additional force fields (e.g., flow field, acoustic field, and magnetic field) to increase the departure force and tuning the electrode surface to reduce the holding force on the gas bubble. ,,,− Manifold microchannels have been proposed to manage the flow resistance and instabilities of two-phase flow. , To promote bubble detachment, the Reynolds number was carefully controlled to increase liquid shear force and remove gas bubbles on the solid surface.…”

“…23,27−36 Two growth patterns and related parameters such as liquid density and supersaturation (superheat) have been proposed and confirmed in numerical and experimental investigations. 31,32,37 It is found that the growth of bubbles can induce local convective flows near the gas−liquid interface and enhance mass transport. As bubbles detach from the electrode, they will also generate a transient turbulent wake that greatly enhance the local mixing of the species and decreases the concentration gradients near the trajectory, which bolsters the local mass and energy transport process and increases system efficiency.…”

“…As bubbles detach from the electrode, they will also generate a transient turbulent wake that greatly enhance the local mixing of the species and decreases the concentration gradients near the trajectory, which bolsters the local mass and energy transport process and increases system efficiency. 31,37,38 However, on the other hand, growing bubble reduces the reaction area of the electrode surface and hinders the chemical reaction. 13,15,19 Practically, the most effective strategy to resolve this dilemma perhaps is to reduce the growth time and accelerate the detachment of the gas bubble at the electrode surface, which usually promotes bubble departure by applying additional force fields (e.g., flow field, acoustic field, and magnetic field) to increase the departure force and tuning the electrode surface to reduce the holding force on the gas bubble.…”

“…10,16,31,38−45 Manifold microchannels have been proposed to manage the flow resistance and instabilities of two-phase flow. 37,46 To promote bubble detachment, the Reynolds number was carefully controlled to increase liquid shear force and remove gas bubbles on the solid surface. Theoretically, bubble detachment is the result of the break off of force balance on the gas bubble between the departure and holding forces.…”