62 citations · 316 across the 26 of their papers we have counts for
27 papers
The spatial organization of wind turbine wakes
Janka Lengyel, Stéphane G. Roux, Patrice Abry +4
Wind turbine wakes play a central role in determining wind farm performance, yet their spatial organization remains only partially understood. Here, we apply a spatially localized…
A non-local traffic flow model for 1-to-1 junctions with buffer
F. A. Chiarello, J. Friedrich, S. GÖttlich
Inthispaper,weintroduceanon-localPDE-ODEtrafficmodeldevotedtothedescriptionof a 1-to-1 junction with buffer. We present an existence result in the free flow case as well as a numer…
Numerical schemes for a class of nonlocal conservation laws: a general approach
Jan Friedrich, Sanjibanee Sudha, Samala Rathan
In this work we present a rather general approach to approximate the solutions of nonlocal conservation laws. In a first step, we approximate the nonlocal term with an appropriate…
Conservation laws with nonlocality in density and velocity and their applicability in traffic flow modelling
Jan Friedrich, Simone Göttlich, Alexander Keimer +1
In this work we present a nonlocal conservation law with a velocity depending on an integral term over a part of the space. The model class covers already existing models in litera…
Conservation laws with nonlocal velocity -- the singular limit problem
Jan Friedrich, Simone Göttlich, Alexander Keimer +1
We consider conservation laws with nonlocal velocity and show for nonlocal weights of exponential type that the unique solutions converge in a weak or strong sense (dependent on th…
Lyapunov stabilization of a nonlocal LWR traffic flow model
Jan Friedrich
Using a nonlocal macroscopic LWR-type traffic flow model, we present an approach to control the nonlocal velocity towards a given equilibrium velocity. Therefore, we present a Lyap…
Lyapunov stabilization for nonlocal traffic flow models
Jan Friedrich, Simone Göttlich, Michael Herty
Using a nonlocal second-order traffic flow model we present an approach to control the dynamics towards a steady state. The system is controlled by the leading vehicle driving at a…
Stochastic interpolation of sparsely sampled time series by a superstatistical random process and its synthesis in Fourier and wavelet space
Jeremiah Lübke, Jan Friedrich, Rainer Grauer
We present a novel method for stochastic interpolation of sparsely sampled time signals based on a superstatistical random process generated from a multivariate Gaussian scale mixt…
Conservation laws with discontinuous flux function on networks: a splitting algorithm
Jan Friedrich, Simone Göttlich, Annika Uphoff
In this article, we present an extension of the splitting algorithm proposed in [22] to networks of conservation laws with piecewise linear discontinuous flux functions in the unkn…
Superstatistical wind fields from point-wise atmospheric turbulence measurements
Jan Friedrich, Daniela Moreno, Michael Sinhuber +2
Accurate models of turbulent wind fields have become increasingly important in the atmospheric sciences, e.g., for the determination of spatiotemporal correlations in wind parks, t…
Single inertial particle statistics in turbulent flows from Lagrangian velocity models
J. Friedrich, B. Viggiano, M. Bourgoin +2
We present the extension of a modeling technique for Lagrangian tracer particles [B. Viggiano et al., J. Fluid Mech.(2020), vol. 900, A27] which accounts for the effects of particl…
An open source MATLAB package to perform basic and advanced statistical analysis of turbulence data and other complex systems
André Fuchs, Swapnil Kharche, Matthias Wächter +1
We present a user-friendly open-source MATLAB\textsuperscript{\textregistered} package developed by the research group Turbulence, Wind energy and Stochastics (TWiSt) at the Carl v…
Explicit construction of joint multipoint statistics in complex systems
J. Friedrich, J. Peinke, A. Pumir +1
Complex systems often involve random fluctuations for which self-similar properties in space and time play an important role. Fractional Brownian motions, characterized by a single…
Network models for nonlocal traffic flow
Jan Friedrich, Simone Göttlich, Maximilian Osztfalk
We present a network formulation for a traffic flow model with nonlocal velocity in the flux function. The modeling framework includes suitable coupling conditions at intersections…
Multi-level stochastic refinement for complex time series and fields: A Data-Driven Approach
M. Sinhuber, J. Friedrich, R. Grauer +1
Spatio-temporally extended nonlinear systems often exhibit a remarkable complexity in space and time. In many cases, extensive datasets of such systems are difficult to obtain, yet…
Nonlocal approaches for multilane traffic models
Jan Friedrich, Simone Göttlich, Elena Rossi
We present a multilane traffic model based on balance laws, where the nonlocal source term is used to describe the lane changing rate. The modelling framework includes the consider…
Stochastic interpolation of sparsely sampled time series via multi-point fractional Brownian bridges
J. Friedrich, S. Gallon, A. Pumir +1
We propose and test a method to interpolate sparsely sampled signals by a stochastic process with a broad range of spatial and/or temporal scales. To this end, we extend the notion…
Probability Density Functions in Homogeneous and Isotropic Magneto-Hydrodynamic Turbulence
J. Friedrich
We derive a hierarchy of evolution equations for multi-point probability density functions in magneto-hydrodynamic (MHD) turbulence. We discuss the relation to the moment hierarchy…
Modelling Lagrangian velocity and acceleration in turbulent flows as infinitely differentiable stochastic processes
Bianca Viggiano, Jan Friedrich, Romain Volk +3
We develop a stochastic model for Lagrangian velocity as it is observed in experimental and numerical fully developed turbulent flows. We define it as the unique statistically stat…
Instanton based importance sampling for rare events in stochastic PDEs
Lasse Ebener, Georgios Margazoglou, Jan Friedrich +2
We present a new method for sampling rare and large fluctuations in a non-equilibrium system governed by a stochastic partial differential equation (SPDE) with additive forcing. To…
Multiscale velocity correlations in turbulence and Burgers turbulence: Fusion rules, Markov processes in scale, and multifractal predictions
Jan Friedrich, Georgios Margazoglou, Luca Biferale +1
We compare different approaches towards an effective description of multi-scale velocity field correlations in turbulence. Predictions made by the operator product expansion, the s…
Maximum principle satisfying CWENO schemes for non-local conservation laws
Jan Friedrich, Oliver Kolb
Central WENO schemes are a natural candidate for higher-order schemes for non-local conservation laws, since the underlying reconstructions do not only provide single point values…
A Godunov type scheme for a class of LWR traffic flow models with non-local flux
Jan Friedrich, Oliver Kolb, Simone Göttlich
We present a Godunov type numerical scheme for a class of scalar conservation laws with non-local flux arising for example in traffic flow models. The proposed scheme delivers more…
Generalized description of intermittency in turbulence via stochastic methods
J. Friedrich, R. Grauer
We present a generalized picture of intermittency in turbulence that is based on the theory of stochastic processes. To this end, we rely on the experimentally and numerically veri…