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Papers by Bendiks Boersma

Research paper thumbnail of Simulating Fibre Suspensions: Lagrangian versus Statistical Approach

Springer Proceedings in Physics, 2009

ABSTRACT Fibre suspensions exhibit complex dynamical flow phenomena and are at the same time of i... more ABSTRACT Fibre suspensions exhibit complex dynamical flow phenomena and are at the same time of immense practical importance, notably in the pulp and paper industries. NTNU and TU Delft have in a collaborative research project adopted two alternative strategies in the simulation of dilute fibre suspensions, namely a statistical approach [2] and a Lagrangian particle treatment [4]. The two approaches have their own advantages and disadvantages. In this paper we aim for the first time to compare the performance of the two.

Research paper thumbnail of Orientation of elongated particles within turbulent flow

Direct and Large-Eddy Simulation VI

... Page 321. 306 JJJ Gillissen, BJ Boersma, and FTM Nieuwstadt Many closure relations for the fo... more ... Page 321. 306 JJJ Gillissen, BJ Boersma, and FTM Nieuwstadt Many closure relations for the fourth moment have been posed in liter-ature. In this work we use the orthotropic closure approximation (Cintra & Tucker 1995). It ...

Research paper thumbnail of Large-Eddy Simulation Applied to an Electromagnetic Flowmeter

Fluid Mechanics and Its Applications, 1994

ABSTRACT Magnetic-inductive flowmeters axe used in several branches of industry, but also in medi... more ABSTRACT Magnetic-inductive flowmeters axe used in several branches of industry, but also in medical applications to measure the blood flow through arterial vessels. The response of a magnetic-inductive flowmeter in turbulent flow is not fully understood. We therefore, solve the appropriate equation, which is in fact Faraday’s Law, for a turbulent flow with a Reynolds number of approximately 50,000 using a Large Eddy Simulation (LES) technique. It is shown that the turbulent fluctuations in the flow have only a very small influence on the induced electric potential.

Research paper thumbnail of Turbulent jet flow noise prediction

The text of the abstract follows. In this paper we describe a numerical approach to completely de... more The text of the abstract follows. In this paper we describe a numerical approach to completely determine the structure of a low Reynolds number compressible jet o w and to compute the associated sound waves in the far eld. The method is applied to simulate a Reynolds number 4; 000, Mach number 0:8 jet, with the results validated by comparison with the jet reproduced experimentally. The mean o w and far eld sound results are shown to while matching conditions are created experimentally inside a low pressure tank. The mean o w results of the DNS are seen to correspond well with our experimental results, and to be compatible with those published in the literature. The semi-analytically obtained sound eld is shown to be identical to that obtained purely by the DNS in the near eld, while in the far eld matches those obtained by us experimentally, and compatible with experimental results previously published.

Research paper thumbnail of Large-Eddy Simulation of Turbulent Flow in a Curved Pipe

Journal of Fluids Engineering, 1996

In this paper, we use Large-Eddy Simulation (LES) to compute a fully-developed turbulent flow in ... more In this paper, we use Large-Eddy Simulation (LES) to compute a fully-developed turbulent flow in a curved pipe. The results allow us to study how the curvature influences the mean velocity profile and also various turbulent statistics. We find reasonable agreement with the few experiments that are available. Our simulation also allows a detailed study of secondary motion in the cross section of the pipe which are caused by the centrifugal acceleration due to the pipe curvature. It is known that this secondary motion may consist of one, two, or three circulation cells. In our simulation results we find one circulation cell.

Research paper thumbnail of Numerical Simulation of Turbulent Flow in Concentric Annuli

Flow, Turbulence and Combustion, 2010

In this paper we consider a fully developed turbulent flow in a round pipe with a small inner ann... more In this paper we consider a fully developed turbulent flow in a round pipe with a small inner annulus. The diameter of the inner annulus is less than 10% of the diameter of the outer pipe. As a consequence, the surface area of the inner pipe compared to the outer pipe is small. The friction exerted by the wall on the flow is proportional to the surface area and the wall shear stress. Due to the small surface area of the inner annulus the additional stress on the flow due to the presence of the annulus may expected to be negligible. However, it will be shown that the inner annulus drastically changes the flow patterns and gives rise to unexpected scaling properties. In previous studies (

Research paper thumbnail of Simulating Fibre Suspensions: Lagrangian versus Statistical Approach

Springer Proceedings in Physics, 2009

ABSTRACT Fibre suspensions exhibit complex dynamical flow phenomena and are at the same time of i... more ABSTRACT Fibre suspensions exhibit complex dynamical flow phenomena and are at the same time of immense practical importance, notably in the pulp and paper industries. NTNU and TU Delft have in a collaborative research project adopted two alternative strategies in the simulation of dilute fibre suspensions, namely a statistical approach [2] and a Lagrangian particle treatment [4]. The two approaches have their own advantages and disadvantages. In this paper we aim for the first time to compare the performance of the two.

Research paper thumbnail of Orientation of elongated particles within turbulent flow

Direct and Large-Eddy Simulation VI

... Page 321. 306 JJJ Gillissen, BJ Boersma, and FTM Nieuwstadt Many closure relations for the fo... more ... Page 321. 306 JJJ Gillissen, BJ Boersma, and FTM Nieuwstadt Many closure relations for the fourth moment have been posed in liter-ature. In this work we use the orthotropic closure approximation (Cintra & Tucker 1995). It ...

Research paper thumbnail of Large-Eddy Simulation Applied to an Electromagnetic Flowmeter

Fluid Mechanics and Its Applications, 1994

ABSTRACT Magnetic-inductive flowmeters axe used in several branches of industry, but also in medi... more ABSTRACT Magnetic-inductive flowmeters axe used in several branches of industry, but also in medical applications to measure the blood flow through arterial vessels. The response of a magnetic-inductive flowmeter in turbulent flow is not fully understood. We therefore, solve the appropriate equation, which is in fact Faraday’s Law, for a turbulent flow with a Reynolds number of approximately 50,000 using a Large Eddy Simulation (LES) technique. It is shown that the turbulent fluctuations in the flow have only a very small influence on the induced electric potential.

Research paper thumbnail of Turbulent jet flow noise prediction

The text of the abstract follows. In this paper we describe a numerical approach to completely de... more The text of the abstract follows. In this paper we describe a numerical approach to completely determine the structure of a low Reynolds number compressible jet o w and to compute the associated sound waves in the far eld. The method is applied to simulate a Reynolds number 4; 000, Mach number 0:8 jet, with the results validated by comparison with the jet reproduced experimentally. The mean o w and far eld sound results are shown to while matching conditions are created experimentally inside a low pressure tank. The mean o w results of the DNS are seen to correspond well with our experimental results, and to be compatible with those published in the literature. The semi-analytically obtained sound eld is shown to be identical to that obtained purely by the DNS in the near eld, while in the far eld matches those obtained by us experimentally, and compatible with experimental results previously published.

Research paper thumbnail of Large-Eddy Simulation of Turbulent Flow in a Curved Pipe

Journal of Fluids Engineering, 1996

In this paper, we use Large-Eddy Simulation (LES) to compute a fully-developed turbulent flow in ... more In this paper, we use Large-Eddy Simulation (LES) to compute a fully-developed turbulent flow in a curved pipe. The results allow us to study how the curvature influences the mean velocity profile and also various turbulent statistics. We find reasonable agreement with the few experiments that are available. Our simulation also allows a detailed study of secondary motion in the cross section of the pipe which are caused by the centrifugal acceleration due to the pipe curvature. It is known that this secondary motion may consist of one, two, or three circulation cells. In our simulation results we find one circulation cell.

Research paper thumbnail of Numerical Simulation of Turbulent Flow in Concentric Annuli

Flow, Turbulence and Combustion, 2010

In this paper we consider a fully developed turbulent flow in a round pipe with a small inner ann... more In this paper we consider a fully developed turbulent flow in a round pipe with a small inner annulus. The diameter of the inner annulus is less than 10% of the diameter of the outer pipe. As a consequence, the surface area of the inner pipe compared to the outer pipe is small. The friction exerted by the wall on the flow is proportional to the surface area and the wall shear stress. Due to the small surface area of the inner annulus the additional stress on the flow due to the presence of the annulus may expected to be negligible. However, it will be shown that the inner annulus drastically changes the flow patterns and gives rise to unexpected scaling properties. In previous studies (