Supervised machine learning in microfluidic impedance flow cytometry for improved particle size determination

The assessment of particle and cell size in electrical microfluidic flow cytometers has become common practice. Nevertheless, in flow cytometers with coplanar electrodes accurate determination of particle size is difficult, owing to the inhomogeneous electric field. Pre-defined signal templates and compensation methods have been introduced to...

Stability of a Tidal Marsh Under Very High Flow Velocities and Implications for Nature-Based Flood Defense

Nature-based strategies, such as wave attenuation by tidal marshes, are increasingly proposed as a complement to mitigate the risks of failure of engineered flood defense structures such as levees. However, recent analysis of historic coastal storms revealed smaller dike breach dimensions if there were natural, high tidal marshes in front of...

Passing vessel interaction: An assessment of MARIN's FlowInteraction module

In order to accurately predict passing vessel interaction forces, different simulation tools have been developed over the years. Many of these are based on a double body flow approach. MARIN (a hydrodynamic research institute located in the Netherlands) developed a simulation tool called the FlowInteraction (FI) module, which is part of the...

Pedestrian flow out of buildings

In this report we describe the phenomenon of pedestrian flow in case of large crowds leaving stadiums, buildings etc. First we made an extensive search through literature existing on this subject. We searched for existing models describing the flow of pedestrians under different conditions. Two researchers from the former Sovjet Union developed...

Modelling of separation using Euler methods

Mathematical modelling and numerical simulation of a two-phase heat transport system condenser

The mathematical modelling and numerical simulation of a condenser is discussed. This mathematical model is part of the NLR approach to model and scale two-phase heat transport systems (for space). During a previous study the condensation length required for various gravity conditions, and working fluids has been investigated by means of...

Numerical simulation of a condenser in two-phase heat transport systems a feasibility study

In this report the numerical simulation of a mathematical model of a condenser is discussed. This mathematical model of the NLR approach to model and scale two-phase heat transport systems. In this report the model of the condenser is reformulated to a model that is suitable for a numerical discussion. The results is a model that is represented...

Technical evaluation report on the AGARD Fluid Dynamics Panel symposium on improvement of aerodynamic performance through boundary layer control and high lift systems

The symposium demonstrated the importance of research in the area of mechanical high-lift systems for transport aircraft to improve the total performance of current transports. Computational techniques are shown to provide new tools for high-lift design. With regard to drag reduction by laminar flow control it is concluded that the information...

Application of a constrained inverse method in the aerodynamic design of a low speed wing-slat configuration

At NLR a system for the computational design on multi-element airfoil has been developed. This design system solves the inverse aerodynamic problem in an approximate way. A priori specified aerodynamic requirements (surface pressure distribution) and geometric requirements are minimized in a least-squares way, introducing weight factors to...

Comparison of boundary layer calculations for the root section of a wing

At the workshop nine participants presented the results of their calculations for a practical test case. The test case deals with the 3D turbulent boundary layer development, including separation, on the root section of a swept wing. The employed calculation methods comprise 3D integral methods as well as field methods. A short description of...

Calculation of the flow around a swept wing, taking into account the effect of the three-dimensional boundary layer. Part II: Wing with laminar boundary layer on the lower surface

The attached flow around a swept wing has been calcTilated with allowance for the effects of boundary layer and wake. In part I a swept wing was considered with a turbulent boundary layer on both the upper and lower wing surface. The present part of the study deals with the calculation of the flow around the same swept wing with a laminar...

Calculation of the flow around a swept wing, taking into account the effect of the three-dimensional boundary layer. Part I: Wing with turbulent boundary layer

The attached flow around a swept wing has been calculated with allowance for the effects of boundary layer and wake. The outer potential flow has been computed with an adapted version of the NLR panel method. The displacement effect of the boundary layer and the wake has been taken into account by the outflow concept. For the calculation of the...

The law of the wall in two- and three- dimensional turbulent boundary layers

The law of the wall has been extended to three-dimensional flows, The effects of both the pressure gradient and the inertial forces have been considered. The deduced wall law is valid when the deviations from the simple two-dimensional law of the wall are small. Agreement with measurements is found within the possible experimental error.

Measurements in a three-dimensional incompressible turbulent boundary layer in an adverse pressure gradient under infinite swept wing conditions

On a wind tunnel model, especially designed to check calculation methods, measurements were made of a three-dimensional turbulent boundary layer under infinite swept wing conditions in an adverse pressure gradient, with a three-dimensional separation near the trailing edge. Accurate measurements of the external flow field, the mean velocity...