arXiv subjects

Fynn Jerome Aschmoneit

Publications and source records attributed to Fynn Jerome Aschmoneit.

5 recordsLinked to original sources

arXiv2026

Similarity Scaling of Fully Developed Mass Transport and Pressure Drop in Oriented Spacer-Filled Channels in Spiral-Wound Membrane Modules

Feed spacers in reverse osmosis membrane modules enhance mass transport but simultaneously increase flow resistance. The quantitative dependence of both on spacer orientation remains poorly understood despite its importance for optimal module design. This work introduces an analytic least-square method for deriving scaling laws governing Sherwood number ($Sh$) and friction factor ($f$) as functions of spacer orientation and Reynolds number ($Re$) through high-resolution computational fluid dynamics simulations. The analytical least-square fitting method provides a systematic approach for extracting transport coefficients. Physical similarity analyses on industrial spacers reveal that mass transport follows $Sh = 3.595(1 + 0.244 \sin(2α)) Re^{1/2}$ while pressure drop scales as $f = 11.63(1 + 0.19 \sin(2α)) Re^{-1/2}$, enabling quantification of orientation-dependent transport efficiency across the full operating range. A novel RO performance analysis scheme shows that the trade-off between water flux and pressure drop crucially depends on the spacer orientation. $45^\circ$-oriented spacers improve the water flux marginally, while increasing the pressure drop significantly, compared to $0^\circ$-oriented spacers.

physics.flu-dyn↗

arXiv2026

Multiscale Cavitation Sub-Grid Modeling via Population Balances as Linear Stochastic Process

A multiscale sub-grid cavitation model is developed in which the bubble size distribution evolves as a linear stochastic process in radius space. Starting from the integrated Rayleigh--Plesset equation, the population balance is recast as a hyperbolic transport equation for the number density per radius, whose method-of-characteristics solution, projected onto a discrete histogram basis, yields a column-stochastic Markov chain governing the bubble counts per size bin. The transition matrix factors into a precomputable, mesh-only geometric part and a local, pressure-dependent shift, isolating the coupling to the surrounding flow into a single dimensionless vector per cell. The framework recovers classical homogeneous-mixture cavitation closures in the limit of a single representative scale.

physics.flu-dyn↗

arXiv2026

Quantifying Flow separation for ellipse and von-Kármán Airfoil: A dataset of surface pressure and skin friction

Steady-state RANS simulations are reported for 2D flow around an ellipse and a von-Kármán-Trefftz airfoil at seven different angles of attack and two different Reynolds numbers, computed using the $k ωSST$ turbulence model in OpenFOAM. The dataset contains surface pressure distribution, skin friction distribution, lift and drag coefficients, stagnation point location and separation point locations. The results serve as a benchmark for calibration and evaluation of extended potential flow models.

physics.flu-dyn↗

arXiv2025

Volume and Surface Area of two Orthogonal, Partially Intersecting Cylinders: A Generalization of the Steinmetz Solid

The intersection of two orthogonal cylinders represents a classical problem in computational geometry with direct applications to engineering design, manufacturing, and numerical simulation. While analytical solutions exist for the fully intersecting case, the Steinmetz solid, partial intersections with arbitrary depth ratios require numerical methods or approximations. This work presents general integral expressions for both the intersection volume and surface area as explicit functions of the intersection depth. Accompanying these exact formulations are empirical approximation functions, which provide closed-form evaluations with relative errors below 15% across the full range of intersection depth. Validation against Quasi-Monte Carlo simulation confirms the accuracy of both the analytical and approximate solutions.

cs.CE↗

arXiv2023

A classification and review of cavitation models with an emphasis on physical aspects of cavitation

This review article presents a summary of the main categories of models developed for modeling cavitation, a multiphase phenomenon in which a fluid locally experiences phase change due to a drop in ambient pressure. The most common approaches to modeling cavitation along with the most common modifications to said approaches due to other effects of cavitating flows are identified and categorized. The application of said categorization is demonstrated through an analysis of selected cavitation models. For each of the models presented, the various assumptions and simplifications made by the authors of the model are discussed, and applications of the model to simulating various aspects of cavitating flow are also presented. The result of the analysis is demonstrated via a visualization of the categorizations of the highlighted models. Using the preceding discussion of the various cavitation models presented, the review concludes with an outlook toward future improvements in the modeling of cavitation.

physics.flu-dyn↗