Inst. Bauingenieurwesen

132 Items

Recent Submissions
Adapting the water management to mitigate the impact of multiple stressors on an urban lake

Ladwig, Robert (2019)

Urban lakes are aquatic ecosystems that are influenced by a water management system and by a possibly strongly sealed urban catchment. The water management aims to fulfill multiple objectives: providing drinking water, sanitation and recreation for the people as well as keeping the ecosystem in a sustainable and resilient state. Urban lakes are facing several stressors. For instance, climate ch...

The assessment of hydrological impacts of climate change and their implications for water management across scales

Lobanova, Anastasia (2019)

The impacts of climate change can become a trigger for critical changes in the spatial and temporal distribution of water resources in many regions in Europe. This will lead from obviously negative effects in some regions to creation of opportunities in others. In the face of future changes: economic, social and environmental, both natural and triggered by anthropogenic activities, the effectiv...

A Novel Slope Failure Operator for a Non-Equilibrium Sediment Transport Model

Zhao, Jiaheng ; Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2018)

Complex transport mechanism and interaction between fluid and sediment make the mathematical and numerical modeling of sediment transport very challenging. Different types of models can lead to different results. This paper investigates a non-equilibrium sediment transport model based on the total load. In this type of model, it is assumed that a bed slide will occur if the bed slope reaches a ...

A depth-averaged non-cohesive sediment transport model with improved discretization of flux and source terms

Zhao, Jiaheng ; Özgen-Xian, Ilhan ; Liang, Dongfang ; Wang, Tian ; Hinkelmann, Reinhard (2019)

This paper presents novel flux and source term treatments within a Godunov-type finite volume framework for predicting the depth-averaged shallow water flow and sediment transport with enhanced the accuracy and stability. The suspended load ratio is introduced to differentiate between the advection of the suspended load and the advection of water. A modified Harten, Lax and van Leer Riemann sol...

Comparison of depth-averaged concentration and bed load flux sediment transport models of dam-break flow

Zhao, Jiaheng ; Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2017)

This paper presents numerical simulations of dam-break flow over a movable bed. Two different mathematical models were compared: a fully coupled formulation of shallow water equations with erosion and deposition terms (a depth-averaged concentration flux model), and shallow water equations with a fully coupled Exner equation (a bed load flux model). Both models were discretized using the cell-c...

An improved multislope MUSCL scheme for solving shallow water equations on unstructured grids

Zhao, Jiaheng ; Özgen-Xian, Ilhan ; Liang, Dongfang ; Wang, Tian ; Hinkelmann, Reinhard (2018-10-19)

This paper describes an improved vector manipulation multislope monotone upstream-centred scheme for conservation laws (MUSCL) reconstruction for solving the shallow water equations on unstructured grids. This improved MUSCL reconstruction method includes a bigger stencil for the interpolation and saves time for determining the geometric relations compared to the original vector manipulation me...

Improved multislope MUSCL reconstruction on unstructured grids for shallow water equations

Zhao, Jiaheng ; Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2018)

In shallow water flow and transport modeling, the monotonic upstream‐centered scheme for conservation laws (MUSCL) is widely used to extend the original Godunov scheme to second‐order accuracy. The most important step in MUSCL‐type schemes is MUSCL reconstruction, which calculate‐extrapolates the values of independent variables from the cell center to the edge. The monotonicity of the scheme is...

Fully coupled robust shallow water flow and sediment transport model on unstructured grids

Zhao, Jiaheng (2019)

This Ph.D. thesis advances the fully coupling of robust shallow water flow and sediment transport modeling. The first part mainly focuses on the multislope MUSCL reconstruction for shallow water flow on unstructured grids. A limitation method for reconstruction of velocities avoids extremely high values for wet/dry fronts. The reconstruction methods are tested via analytical benchmarks and lab...

Modeling the impacts of climate extremes and multiple water uses to support water management in the Icó-Mandantes Bay, Northeast Brazil

Matta, Elena ; Koch, Hagen ; Selge, Florian ; Simshäuser, Max Nino ; Rossiter, Karina ; Silva, Gérsica Moraes Nogueira da ; Gunkel, Günter ; Hinkelmann, Reinhard (2018-07-25)

The hydropower production, water supply and aquaculture services of the Itaparica Reservoir are of immense importance for the Brazilian Northeast. Uncontrolled water resources consumption (e.g. irrigation, water supply), climate and land use change effects deteriorated the water quantity and quality in the reservoir, leading to socio-economic and environmental problems. In this work, a depth-av...

Decision making in structural engineering problems under polymorphic uncertainty

Petryna, Yuri ; Drieschner, Martin (2019-02-22)

The treatment of diverse uncertainties is an important challenge in structural engineering problems, especially from the viewpoint of realistic analysis. Inaccuracy and variability are always present and have to be quantified by either probabilistic, possibilistic, polymorphic or other uncertainty approaches. Regardless to the applied uncertainty quantification method, the numerical predictions...

Parameterization of arbitrary hole shapes using non-destructive testing and resulting stress concentration in a 2D plate with finite dimensions

Drieschner, Martin ; Petryna, Yuri ; Eichner, Lukas (2019-02-21)

Air void inclusions are mostly unavoidable in many different materials resulting from manufacturing processes or environmental conditions. In this contribution, non-destructive testing (NDT) like computer tomography (CT) is used for air void detection and quantification. The air voids lead to stress concentrations around them which influence significantly the structural integrity and at worst, ...

Acquisition of polymorphic uncertain data based on computer tomographic scans and integration in numerical models of adhesive bonds

Drieschner, Martin ; Petryna, Yuri (2019-02-21)

Since commercial wind turbines were introduced around 1980, the length of rotor blades has increased substantially up to 80m with consequently higher demands on availability and failure prevention. One of the typical failure mechanisms of rotor blades in operation are fatigue cracks in adhesive bonds often caused by air voids with a-priori unknown properties, which results from the manufacturi...

Electronic Supplementary to Doctoral Dissertation

Lobanova, Anastasia (2018)

This Electronic Supplementary contains the SWIM Model set up, calibrated and validated for all eight river basins, together with executables, used to perform modelling experiments for Doctoral Thesis "The assessment of hydrological impacts of climate change and their implications for water management across scales: from the local to European scale"

Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications

Zhou, Kuangxin ; Stüber, Johan ; Schubert, Rabea-Luisa ; Kabbe, Christian ; Barjenbuch, Matthias (2017)

Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the...

Towards time- and state-dependent seismic risk over urban scales

Haas, Michael (2019)

Probabilistic seismic risk assessment involves the appraisal of three components: the seismic hazard due to expected ground motions, the exposure, i.e., assets exposed to the hazard, and their vulnerability with respect to the hazard. Earthquake sequences are a result of a time dependent process, which is complex to consider in a probabilistic framework. It is thus common to reduce sequences to...

Phosphorus recovery from municipal and fertilizer wastewater: China's potential and perspective

Zhou, Kuangxin ; Barjenbruch, Matthias ; Kabbe, Christian ; Inial, Goulven ; Remy, Christian (2017)

Phosphorus (P) is a limited resource, which can neither be synthesized nor substituted in its essential functions as nutrient. Currently explored and economically feasible global reserves may be depleted within generations. China is the largest phosphate fertilizer producing and consuming country in the world. China's municipal wastewater contains up to 293,163 Mg year of phosphorus, which equa...

Comparative environmental life cycle assessment of phosphorus recovery with different generations of the AirPrex® systems

Zhou, Kuangxin ; Remy, C. ; Kabbe, C. ; Barjenbruch, M. (2018)

Phosphorus (P) recovery through struvite is already both technically and economically feasible. This has been proved by more than 40 large-scale plants worldwide. However, when designing and implementing these P-recovery technologies, the environmental effects need to be considered. Therefore, a comparative environmental life cycle assessment of phosphorus recovery with different generations of...

Unterraumbasierte Detektion von Strukturschäden an Jacket-Gründungen von Offshore-Windenergieanlagen

Hille, Falk (2018)

Die vorliegende Arbeit beschreibt die Adaption eines globalen, schwingungsbasierten Verfahrens zur frühzeitigen Erkennung von Strukturschäden an Gründungsstrukturen offshore installierter Windenergieanlagen (OWEA). Damit soll es Betreibern von Offshore-Windparks ermöglicht werden, im Rahmen periodisch durchgeführter messtechnischer Überwachungsmaßnahmen mit einem gegenüber wiederkehrender Inspe...

Bitumen und Chemometrie

Weigel, Sandra (2018)

Im Rahmen dieser Arbeit konnte gezeigt werden, dass mithilfe der Fourier-Transformations-Infrarotspektroskopie und der Anwendung multivariater Analysemethoden eine umfassende Charakterisierung von Bitumenproben möglich ist. Als Grundlage dienten 90 Straßenbaubitumen unterschiedlicher Herkunft, Alterungsstufe und Sorte, die mithilfe verschiedener chemischer und physikalischer Verfahren untersuch...

Simulations of nutrient emissions from a net cage aquaculture system in a Brazilian bay

Matta, Elena ; Selge, Florian ; Gunkel, Günter ; Rossiter, Karina ; Jourieh, Ayman ; Hinkelmann, Reinhard (2016)

Hydrodynamics and transport simulations were conducted with the modeling software TELEMAC-2D on Icó-Mandantes bay, a branch of the Itaparica reservoir. The bay has a maximal operational water level amplitude of 5 m and is suffering from eutrophication and algae bloom. Therefore, we investigated low and high water level scenarios with two different high resolution meshes, with the purpose to dee...