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The Maisotsenko cycle (M-cycle) heat exchangers have emerged as a promising technology due to their potential for high heat transfer rates and sustainable cooling. However, previous studies have lacked comprehensive three-dimensional modeling to evaluate the effects of geometry, relative humidity, and airflow on heat exchanger performance. To address this gap, this study presents an optimized performance analysis of M-cycle heat exchangers using OpenFOAM. The research examines the impact of key parameters, including fluid flow rate, inlet humidity, and channel geometry, on heat transfer efficiency. Results indicate that reducing inlet humidity and increasing flow rate improves heat transfer, while channel geometry is critical to performance. Higher humidity in both the wet and dry channels minimizes the effectiveness of the heat exchanger. Additionally, parallel flow configurations outperform counter-flow setups, showing an 18 % higher efficiency and a 20 % increase in the Nusselt number. The efficiency of the heat exchanger ranged between 0.54 and 0.73, underscoring the importance of optimizing design parameters for different operating conditions. These findings offer valuable insights into addressing global energy efficiency challenges and advancing climate control technologies, providing practical guidance for engineers and researchers in sustainable cooling solutions.

The temperature of battery packs is a crucial concern for electric vehicles' performance, reliability, and lifespan. The air-cooling systems of batteries are considered more important because of their simple structure design, economic aspect, and lightweight to control the thermal behavior of battery packs. A numerical investigation of three-dimensional models based on computational fluid dynamics consisting of 32 cylindrical cells of lithium-ion battery packs in regular, staggered, and zigzag arrangements is presented to evaluate the thermal behavior of air-cooled systems for lithium battery packs subjected to various air velocities and discharge rates. The results demonstrate that the regular arrangement along the horizontal direction flow has the most effective cooling performance, and best heat dissipation. The zigzag arrangement and the staggered arrangement are ranked next, respectively. Due to the change in velocity from 2 m/s to 5 m/s, the maximum temperature of battery packs decreased by 2.05 K, 1.68 K, and 2.31 K and the energy used to provide cooling air increased by 80.32 %, 75.48 %, and 78.36 %in regular, zigzag, and staggered arrangement, respectively. Further, the maximum temperature and the efficiency factor have a reduction trend versus increasing velocities. When the discharge rate is enhanced, the heat generation rises by an external source, hence the maximum temperature increases by 301.64 K for 1C, 305.67 K for 1.5 C, and 310.84 K for 2 C in the regular arrangement as the effective case in cooling performance. This current study offers valuable recommendations for the expanded battery packs in electric vehicles with a comprehensive simulation that is almost impossible to investigate in physical experiments.

Introduction: Vocal folds are responsible for sound generation. In unilateral vocal fold paralysis (UVFP), the recurrent laryngeal nerve, which controls the vocal folds, is paralyzed. Medialization laryngoplasty is a surgery in which an implant is inserted to push the paralyzed vocal fold to the centerline to recover phonation. Methods: Here, a numerical simulation is used to calculate flow-related parameters to give insight into what happens in healthy and treated(implanted) vocal folds and their enhancement. In the present work, airflow over vocal folds is modeled considering fluid-structure interaction (FSI) and varying inlet pressure. The governing equations are discretized for fluid and solid domains and solved using the Galerkin finite element method. The boundary conditions for healthy and unilaterally paralyzed vocal folds were imposed to agree with real cases behavior. Results: The results showed the effectiveness of medialization laryngoplasty in treating unilateral vocal fold paralysis concerning healthy vocal folds. Conclusion: This simulation provided a better insight into treatment results for patient-specific cases.

Introduction: Computational modeling is one of the best non-invasive approaches to predicting the functional behavior of the mitral valve (MV) in health and disease. Mitral valve prolapse (MVP) due to partial or complete chordae tendineae rapture is the most common valvular disease and results in mitral regurgitation (MR). Methods: In this study, Image-based fluid-structure interaction (FSI) models of the human MV are developed in the normal physiological and posterior leaflet prolapse conditions. Detailed geometry of the healthy human MV is derived from Computed Tomography imaging data. To provide prolapse condition, some chords attached to the posterior leaflet are removed from the healthy valve. Both normal and prolapsed valves are embedded separately in a straight tubular blood volume and simulated under physiological systolic pressure loads. The Arbitrary Lagrangian-Eulerian finite element method is used to accommodate the deforming intersection boundaries of the blood and MV. Results: The stress values in the mitral components, and also flow patterns including the regurgitant flow rates are obtained and compared in both conditions through the simulation. These simulations have the potential to improve the treatment of patients with MVP, and also help surgeons to have more realistic insight into the dynamics of the MV in health and prolapse. Conclusion: In the prolapse model, computational results show incomplete leaflet coaptation, higher MR severity, and also a significant increment of posterior leaflet stress compared to the normal valve. Moreover, it is found more deviation of the regurgitant jet towards the left atrium wall due to the posterior leaflet prolapse.

Over the last few decades, researchers have been focusing on determining the critical attack angle at which dynamic stall occurs. This angle is usually determined by solving the Navier-Stokes equations, which include viscosity, pressure, gravity, and acceleration terms. However, Navier-Stokes equations are quite complex to solve and consequently difficult to simulate, thus the simulation is not accurate enough. Therefore, this article predicts the critical attack angle for the first time using Euler equations devoid of viscous terms. One of the key advantages of Euler equations is their ability to capture the vortices and predict stall dynamics. The Euler equations are thus integrated and the resulting equations are discretized using the finite volume method. A first-order upwind-based method is used to calculate the convective fluxes at the cell boundaries in the finite volume approach. A NACA 0012 airfoil is chosen for this study at various attack angles with a Mach number of 0.3. Based on the justification of Crocco's theorem, the Euler equations successfully act as Navier-Stokes equations. The vortex patterns are found to behave independently of the artificial dissipation. All the vortices are successfully predicted using the inviscid governing equations. The numerical results obtained are validated by other published experimental and numerical data.

Controlling noise pollution is one of the most crucial parameters in various industries. The use of elastic plates has a substantial impact on noise pollution control and associated factors, such as transmission loss. Additionally, the transmission loss is affected by geometric variations. However, the effect of a rib and elastic plate on the acoustic properties of a channel for a wide range of Reynolds numbers has not yet been investigated, although their use could reduce noise pollution. This study thus investigates the acoustic and flow impacts of a rib and an elastic plate. The control variables for fluid-structure–acoustic coupling numerical simulations are rib height, rib angle, elastic plate length, elastic plate position, Reynolds number, and the Young module of the elastic plate. The governing equations are discretized using the Galerkin method. The results indicate that the transmission loss is 27% more at the elastic plate’s highest position. By decreasing the length of the elastic plate by 50%, the mean transmission loss is reduced by 9%. The findings of this study can be utilized by mechanical and aerospace engineers in the design of aircraft, automobiles, and cooling and heating systems, particularly fan coils.