Internal Flow Choking in Cardiovascular System: A Radical Theory in the Risk Assessment of Asymptomatic Cardiovascular Diseases

The theoretical discovery of Sanal flow choking in the cardiovascular system (CVS) demands for interdisciplinary studies and universal actions to propose modern medications and to discover new drugs to annul the risk of flow-choking leading to shock-wave generation causing asymptomatic-cardiovascular-diseases. In this chapter we show that when blood-pressure-ratio (BPR) reaches the lower-critical-hemorrhage-index (LCHI) the flow-choking could occur in the CVS with and without stent. The flow-choking is uniquely regulated by the biofluid/blood-heat-capacity-ratio (BHCR). The BHCR is well correlated with BPR, blood-viscosity and ejection-fraction. The closed-form analytical models reveal that the relatively high and the low blood-viscosity are cardiovascular-risk factors. In vitro data shows that nitrogen, oxygen, and carbon dioxide gases are predominant in fresh blood samples of the human being/Guinea-pig at a temperature range of 37–40 °C (98.6–104 °F). In silico results demonstrate the occurrence of Sanal flow choking leading to shock wave generation and pressure-overshoot in CVS without any apparent occlusion. We could conclude authoritatively, without any ex vivo or in vivo studies, that the Sanal flow choking in CVS leads to asymptomatic-cardiovascular-diseases. The cardiovascular-risk could be diminished by concurrently lessening the viscosity of biofluid/blood and flow-turbulence by increasing the thermal-tolerance level in terms of BHCR and/or by decreasing the BPR

Evaluation of chemical kinetic models for simulations of hydrogen detonations by comparison with experimental data

Two-dimensional numerical simulations of a weakly unstable detonation mixture 2H2+O2+3.76Ar at 20kPa and 295K were performed using our validated OpenFOAM solver based on reacting-PimpleCentralFoam. This study compared the detonation dynamics obtained with four chemical models, namely Hong 2011, Burke 2012, Mével 2014, and FFCM-2 with recently obtained experimental results. The experimental–numerical comparisons were performed in threefold: (i) quantitative comparisons of the cell sizes (λ) and their distributions (2σ/λ); (ii) qualitative comparisons of the detonation structure based on simultaneous planar laser-induced fluorescence of both nitric oxide (NO-PLIF) and OH radical (OH-PLIF); (iii) qualitative and quantitative comparisons of the detonation dynamics based on combined Rayleigh scattering and NO-PLIF measurements. The simulations conducted with Hong 2011’s, Burke 2012’s, and FFCM-2’s models satisfactorily reproduced the average cell size (within 10%), while it was 1.5 times smaller with Mével 2014’s model. The opposite trends were observed in cell size distributions (2σ/λ) with satisfactory predictions from Mével 2014’s model (within 25%) and almost no cell size variations (2σ/λ < 0.1) for the other models. By comparing the simultaneous NO- and OH-PLIF imaging, the simulations conducted with FFCM-2’s and Mével 2014’s models qualitatively reproduced the reaction zone structure, while more discrepancies were obtained with Hong 2011’s and Burke 2012’s models. Quantitatively, simulations conducted with FFCM-2’s and Mével 2014’s models presented the lowest discrepancy (below two-fold) at reproducing the induction zone dynamics along the cellular cycle, while large discrepancies (approximately three-fold) were observed with Hong 2011’s and Burke 2012’s models. Chemical timescale analyses evidenced the relation between the faster reaction timescales of Mével 2014’s model and the ability to reproduce the experimental variability on both λ and Δi. These detailed comparisons emphasized the importance of the chemical model selection and the need for combined experimental measurements to both validate chemical models and achieve predictive detonation simulations

Experimental&ndash;Numerical Comparison of H2&ndash;Air Detonations: Influence of N2 Chemistry and Diffusion Effects

This study evaluates the performance of two-dimensional (2D) detonation simulations against recent experimental measurements for a stoichiometric hydrogen&ndash;air mixture at 25 kPa. The validation parameters rely on the average cell size (&lambda;), the cell size variability (2&sigma;/&lambda;), and the dynamics of both the relative detonation speed (D/DCJ) and the local induction zone length (&Delta;i) along the cell cycle. We select M&eacute;vel 2017&rsquo;s and San Diego&rsquo;s chemical models for 2D simulations, after evaluating 13 chemical models with Zeldovich&ndash;von Neumann&ndash;D&ouml;ring (ZND) simulations. From this model selection, the effects of nitrogen chemistry and diffusion (Navier&ndash;Stokes or Euler equations) are evaluated on the validation parameters. The main findings are as follows: the simulations conducted with the M&eacute;vel 2017 (with N2 chemistry) model provide the best agreement with &lambda;meanexp (&asymp;17%), while the experimental cell variability (2&sigma;/&lambda;) is reproduced within 20% by most simulation cases. This model (M&eacute;vel 2017 with N2 chemistry) also presents good agreement with both the &Delta;i and D/DCJ dynamics, whereas San Diego&rsquo;s simulations under-predict them along the cell. Interestingly, the speed decay along the cell length exhibits self-similar behavior across all cases, suggesting independence from cell size variability, unlike the &Delta;i dynamics. Finally, this study demonstrates the minimal impact of the diffusion on the simulation results

A Validation of Material, Design, and Physical Properties of Weightlifting Shoes Based on 3D Models

559-566This research paper explores the enhancement of weightlifting shoe (WLS) performance through a unique combination of physical analysis (PHA) and finite element analysis (FEA). While FEA is extensively employed in diverse design fields, its application to optimizing weightlifting shoes remains unprecedented. WLS underwent comprehensive physical testing, including evaluations of energy absorption, density determination, abrasion resistance, slip resistance, and compression, with subsequent calculation of mean values. Utilizing Creo software, 3D models of WLS soles were created and imported into the ANSYS workbench for detailed analysis. This analysis encompasses the assessment of critical parameters like total deformation, directional deformation, von mises stress, and von mises strain. The outcomes of this study offer a promising framework for enhancing the quality, design, and performance of weightlifting shoes, potentially benefiting both athletes and manufacturers in the field