scholarly journals Generalised Navier boundary condition for a volume of fluid approach using a finite-volume method

2019 ◽  
Vol 31 (2) ◽  
pp. 021203 ◽  
Author(s):  
Arnout M. P. Boelens ◽  
Juan J. de Pablo
Keyword(s):  
Boundary Condition ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Volume Of Fluid ◽  
Navier Boundary Condition ◽  
Volume Method

scholarly journals A Low Dissipative and Stable Cell-Centered Finite Volume Method with the Simultaneous Approximation Term for Compressible Turbulent Flows

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1206
Author(s):  
Myeongseok Kang ◽  
Donghyun You
Keyword(s):  
Boundary Condition ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Simultaneous Approximation ◽  
Summation By Parts ◽  
Eddy Simulation ◽  
Characteristic Boundary ◽  
Simultaneous Approximation Term ◽  
Characteristic Boundary Condition ◽  
Volume Method

A simultaneous-approximation term is a non-reflecting boundary condition that is usually accompanied by summation-by-parts schemes for provable time stability. While a high-order convective flux based on reconstruction is often employed in a finite-volume method for compressible turbulent flow, finite-volume methods with the summation-by-parts property involve either equally weighted averaging or the second-order central flux for convective fluxes. In the present study, a cell-centered finite-volume method for compressible Naiver–Stokes equations was developed by combining a simultaneous-approximation term based on extrapolation and a low-dissipative discretization method without the summation-by-parts property. Direct numerical simulations and a large eddy simulation show that the resultant combination leads to comparable non-reflecting performance to that of the summation-by-parts scheme combined with the simultaneous-approximation term reported in the literature. Furthermore, a characteristic boundary condition was implemented for the present method, and its performance was compared with that of the simultaneous-approximation term for a direct numerical simulation and a large eddy simulation to show that the simultaneous-approximation term better maintained the average target pressure at the compressible flow outlet, which is useful for turbomachinery and aerodynamic applications, while the characteristic boundary condition better preserved the flow field near the outlet.

Finite Volume Method for Fractional Maxwell Viscoelastic Fluid Over a Moving Plate With Convective Boundary Condition

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Jinhu Zhao
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Viscoelastic Fluid ◽  
Convective Boundary Condition ◽  
Moving Plate ◽  
Convective Boundary ◽  
Flow And Heat Transfer ◽  
Volume Method

Abstract A novel finite volume method about the boundary layer flow and heat transfer of fractional viscoelastic fluid over a moving plate with convective boundary condition is developed. The fractional Maxwell model and fractional Fourier's law are employed in the constitutive relations. Numerical solutions are obtained and validated by exact solutions of special case with source terms. The effects of fractional parameters on the flow and heat transfer characteristics are analyzed. Results show that the viscoelastic fluid performs shear-thickening property with the increase of fractional parameter. Moreover, the variations of the average Nusselt number demonstrate that the viscoelastic fluid characterized by fractional Fourier's law has short memory in heat conduction process.

scholarly journals Simulasi CFD pada Kapal Planing Hull

Kapal ◽  
2019 ◽  
Vol 16 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Samuel Samuel ◽  
Andi Trimulyono ◽  
Ari Wibawa Budi Santosa
Keyword(s):  
Froude Number ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Volume Of Fluid ◽  
Navier Stokes ◽  
Reynolds Averaged Navier Stokes ◽  
Volume Method

Akurasi dalam memprediksi hambatan kapal adalah salah satu aspek penting dalam mendesain lambung kapal. Secara umum, hambatan kapal dengan type planing lebih rumit daripada type displacement. Planing hull memiliki karakteristik unik seperti trim, heave, hard-chine, Froude number tinggi dan dead-rise angle. Gaya hidrodinamik pada planing hull lebih dominan daripada gaya hidrostatik. Analisis numerik menggunakan Finite Volume Method (FVM) dipilih untuk menyelesaikan masalah hidrodinamik. Dalam penelitian ini, persamaan (RANS Reynolds-Averaged Navier-Stokes) digunakan untuk menggambarkan model turbulensi dengan k-ε. Secara umum, pemodelan Volume of Fluid (VOF) menggunakan aliran multiphase Euler yang diasumsikan air dan udara sebagai phase. Tujuan dari penelitian ini adalah untuk memperkenalkan perhitungan kapal type planing hull untuk memprediksi hambatan kapal dan seakeeping. Studi validasi ini dilakukan dengan menggunakan eksperimen Fridsma hullform. Hasil pada penelitian ini menunjukkan bahwa simulasi numerik pada jenis planing hull dapat diprediksi dengan akurasi yang cukup baik.

scholarly journals Prediksi Hambatan Kapal dengan Menggunakan Metode Overset Mesh pada Kapal Planing Hull

2020 ◽  
Vol 4 (1) ◽  
pp. 24-34
Author(s):  
Abubakar Fathuddiin ◽  
Samuel Samuel ◽  
Kiryanto Kiryanto ◽  
Aulia Widyandari
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Volume Of Fluid ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Ship Resistance ◽  
High Speeds ◽  
Mesh Method ◽  
Reynolds Averaged Navier Stokes ◽  
Volume Method

ABSTRAKPrediksi hambatan kapal tipe planing lebih rumit dibanding dengan tipe displacement, hal ini disebabkan oleh gaya hidrodinamis yang lebih dominan pada bagian bawah kapal. Karakteristik hambatan kapal tipe planing sangat dipengaruhi oleh gerakan trim dan heave. Selain itu, bentuk hullform juga mempengaruhi hambatan kapal; seperti sudut dead-rise, chine, strip, stephull, dan lain-lain. Solusi untuk memprediksi hambatan kapal dengan menggunakan Finite Volume Method (FVM). Persamaan RANS (Reynolds- Averaged Navier-Stokes) dengan model turbulensi k-ε untuk memprediksi aliran turbulen dan Volume of Fluid (VOF) untuk mempresentasikan aliran 2 fasa. Pada penelitian ini digunakan metode overset mesh untuk memprediksi hambatan kapal agar mendapatkan akurasi yang baik. Hasil simulasi hambatan menunjukkan trend yang baik. Pada kecepatan tinggi, prediksi hambatan tidak memiliki hasil yang baik. Solusi yang ditawarkan pada Numerical ventilation problem (NVP) adalah dengan menggunakan metode phase replacement.Kata kunci: CFD, planing hull, RANS, overset mesh, NVP ABSTRACTThe prediction of planing hull resistance is more complicated than the displacement hull. It is caused by the more dominant hydrodynamic force at the bottom of the ship. The planing hull resistance characteristics are strongly influenced by trim and heave movements. In addition, the shape of the hullform also affects the ship's resistance, such as dead-rise angle, chine, strip, stephull, and others. The solution to predict ship resistance is by using the Finite Volume Method (FVM). RANS (Reynolds-Averaged Navier-Stokes) equation k-ε turbulence model was used to predict turbulent flow and Volume of Fluid (VOF) to present 2 phase flow. In this study, the overset mesh method was used to predict ship resistance in order to get good accuracy. Resistance simulation results showed a good trend. At high speeds, the prediction of resistance did not have good results. The solution offered in the Numerical ventilation problem (NVP) was to use the phase replacement method.Keywords: CFD, planing hull, RANS, overset mesh, NVP

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