Lagrangian averaging (LA) is producing new ideas and methods for the construction of novel subgrid models for momentum, energy and scalar transport in turbulence. LA is applied at fixed Lagrangian fluid label, rather than at fixed spatial location, as in Eulerian averaging and filtering for RANS and LES equations, respectively. Instead, LA is performed in a frame of motion that follows along wi...

In numerous industries such as drilling, peening, cleaning, etc., a cavitating jet is adopted. However, it challenging to simulate the flow field numerically with accuracy. The of organ pipe cavitation nozzle simulated in this research using RNG k−ε, DES, and LES turbulence models. model can more accurately predict periodic shedding cloud, which basically consistent morphology captured high−spe...

This paper proposes a data-driven turbulence model for predicting the mean flow in turbulent circular jets over wide range of Reynolds numbers (Re). The main formulation is adapted from well-known k–ε (where k kinetic energy, and ε dissipation rate) with set Re-dependent variation constants. Tam–Thies correction applied constants optimized using data assimilation based on ensemble Kalman filter...

Let C be a system (finite or infinite) of centrally symmetric convex bodies in IR with disjoint interiors; we call such a C a packing . For a real number ε > 0 and for C ∈ C, we let C denote C enlarged by the factor 1+ ε from its center, that is, C = (1+ ε)(C − c) + c, where c stands for the center of symmetry C. Let us call the closure of the set C \C the ε-ring of C. We call the system C = {C...

Abstract We introduce a framework for statistical inference of the closure coefficients using machine learning methods. The objective this is to quantify epistemic uncertainty associated with model by experimental data via Bayesian statistics. tailored towards cases which limited amount available. It consists two components. First, treating all latent variables (non-observed variables) in as st...

Let k be a an algebraically closed field of arbitrary characteristic, and we let h : A(k(t)) −→ R≥0 be the usual Weil height for the n-dimensional affine space corresponding to the function field k(t) (extended to its algebraic closure). We prove that for any affine variety V ⊂ A defined over k(t), there exists a positive real number ε := ε(V ) such that if P ∈ V (k(t)) and h(P ) < ε, then P ∈ ...

Free-convection flow through a two-dimensional rectangular box having openings at opposite corners on the vertical walls is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. Convection is induced when the box's ceiling or its floor is imposed with a temperature that is different to that of the ambient fluid, while all other walls are insulated. Th...

In this paper, the effect of air turbulence intensity on the flame structure in various radii and lengths of a flame holder numerically studied. Finite volume method is used to solve the governing equations. The obtained numerical results using realizable k-ε and β-PDF models show a good agreement with the experimental data. The results show that flame holder with greater lengths yield shorter ...