Valentin Heller

University of Nottingham | Notts · Department of Civil Engineering

For millennia, societal progress, health and prosperous economic growth has been closely linked to development of water infrastructure. Now in the 21st century, humankind faces some immense challenges including increasing and migrating populations, water and food security, damaged ecosystems, and a growing energy crisis, all coupled with the effect...

Wave impact on offshore and coastal structures, such as oil and gas rigs, offshore wind turbine platforms, breakwaters, food protection systems and wave energy converters, involve complex wave-structure interactions. These interactions are particularly challenging for flexible structures and may result in structural damage in extreme cases. Some st...

Impulse waves are generated by landslides, rockfalls and iceberg calving in water bodies such as lakes and reservoirs. These waves represent a persistent danger for dams, e.g. in the 1963 Vajont disaster an impulse wave impacted and overtopped the Vajont dam causing approximately 2000 causalities. Unfortunately, an accurate prediction of the effect...

Potentially devastating tsunamis are generated by landslides impacting into water bodies. Such subaerial landslide-tsunamis are typically predicted with empirical equations, which, however, fail to appropriately capture some of the underlying physics. Considering the spectral composition of subaerial landslide-tsunamis provides new physical insight...

Coastal structures, such as oil and gas rigs, offshore wind turbine platforms, breakwaters, flood protection systems and wave energy converters, need to be appropriately designed to withstand wave loading. These structures experience stresses under wave loading and may significantly deform. A mutual interaction is triggered between the waves and st...

Physical modelling in the laboratory is widely used for hydraulic investigations. Froude similarity results in significant scale effects in small models for flows involving air-entrainment. Such air-water flows are essential for many hydraulic applications and physical processes including spillways, hydraulic jumps, wave breaking and plunging jets....

Subaerial landslide-tsunamis (SLTs) are generated by mass movements impacting into water bodies. Past cases, such as the Vajont landslide-tsunami event in 1963, which caused approximately 2000 casualties, demonstrate their significant hazard potential. SLT generation highly depends on the mass movement type (MMT) involving sliding, falling, flowing...

Hydraulics is the branch of science and technology concerned with the conveyance of liquids through pipes and channels. Hydraulics has a wide range of applications in open channel flows, renewable energy, pipe flows and natural hazards. It typically concerns the quantification of the discharge, water depth, fluid forces and sometimes the entrainmen...

The Froude scaling laws have been used to model a wide range of water flows at reduced size for almost a century. In such Froude scale models, significant scale effects for air–water flows (e.g. hydraulic jumps or wave breaking) are typically observed. This study introduces novel scaling laws, excluding scale effects in the modelling of air–water f...

Glaciers calving icebergs into the ocean significantly contribute to sea-level rise and can trigger tsunamis, posing severe hazards for coastal regions. Computational modeling of such multiphase processes is a great challenge involving complex solid–fluid interactions. Here, a new continuum damage Material Point Method has been developed to model d...

Landslides, rockfalls, and iceberg calving impacting into a water body generate large landslide-tsunamis posing a serious hazard in lakes and reservoirs. These waves can impact and even overtop dams as in the 1963 Vajont disaster in Italy. However, estimating the effects of tsunamis on dams, e.g. pressures and forces, and 3D effects is challenging....

Impulse waves, such as tsunamis generated by landslides, iceberg calving and rockfalls, endanger infrastructure and humans along reservoir and lake shorelines. These waves may further impact and even overtop dams generating significant forces and potential flooding downstream. Although impulse wave forces and dam overtopping are key design and wave...

Landslide-tsunamis are generated by masses, such as landslides or rockfalls, impacting into water bodies and they resulted in major catastrophes. Generic research into landslide-tsunamis has widely been conducted in idealised water body geometries at uniform water depths. However, varying bathymetries can significantly alter landslide-tsunamis. Thi...

Subaerial landslide-tsunamis (SLTs) are caused by mass movements such as landslides, rock falls or glacier calving. Research into SLTs is ongoing for many decades, however, the advancement in the physical understanding and reliability of hazard assessment methods is not reflecting the number of articles published per year. It appears that a paradig...

Large impulse waves are generated in reservoirs by, e.g., landslides and iceberg calving. Impulse waves result in significant forces when impacting dams and it is important to take these forces into account when designing a dam. The prediction of forces due to extreme waves is still subject to large uncertainties. Analytical models are available fo...

When calving icebergs interact with water, waves of tens of meters in height, so-called iceberg-tsunamis (IBTs), may be generated. Recent examples include an IBT which reached an amplitude of 45 to 50 m in Eqip Sermia, Greenland, in 2014. A novel numerical methodology and unique large-scale laboratory experiments are presented to investigate the ge...

Mass balance analysis of ice sheets is a key component to understand the effects of global warming with iceberg calving as a significant contributor. Calving recently generated tsunamis of up to 50 m in amplitude endangering human beings and coastal infrastructure. Such iceberg-tsunamis (IBTs) have been investigated based on 66 unique large-scale e...

Scale effects are differences in physical behaviour that manifest between a large event and a geometrically‐scaled laboratory model and may cause misleading predictions. This study focuses on scale effects in granular slides, important in the environment and to industry. A versatile 6 m long laboratory set‐up has been built following Froude similar...

This is the 2nd edition of our landslide-generated impulse waves (landslide-tsunamis) manual to predict such waves in lakes and reservoirs including their effects (run-up, force, overtopping volume, etc.) at shorelines and dams. The manual is available here (number 254): https://vaw.ethz.ch/en/the-institute/vaw-communications/2010-2019.html. The co...

Earthquake-tsunamis, including the 2004 Indian Ocean Tsunami and the 2011 Tōhoku Tsunami in Japan, serve as tragic reminders that such waves pose a major natural hazard. Landslide-tsunamis, including the 1958 Lituya Bay case, may exceed 150 m in height and similar waves generated in lakes and reservoirs may overtop dams and cause significant devast...

Editorial for the Special Issue Tsunami Science and Engineering II in the Journal of Marine Science and Engineering.

Calving icebergs falling into water can generate large tsunamis, so-called iceberg-tsunamis. This phenomenon poses a threat for the fishing and shipping industries and coastal communities. Examples in Greenland include a 50 m amplitude wave recorded during an iceberg calving event at the Eqip Sermia glacier in 2014 and a tsunami generated by a caps...

Large landslide-tsunamis are caused by mass movements such as landslides and rock falls impacting into a water body. Landslide-tsunami research is essentially based on the two idealised water body geometries (i) wave flume (2D, laterally confined wave propagation) and (ii) wave basin (3D, unconfined wave propagation). The wave heights in 2D and 3D...

Iceberg calving at outlet glaciers contributes to global sea-level rise in the context of climate change. This study investigates tsunamis generated by iceberg calving, so-called iceberg-tsunamis. Such tsunamis reached amplitudes of 50 m in the recent past and endanger human beings and coastal infrastructure. 66 unique large-scale experiments have...

Large landslide-tsunamis are caused by mass movements such as landslides or rock falls impacting into a water body. Research of these phenomena is essentially based on the two idealised water body geometries (i) wave fume (2D, laterally confined wave propagation) and (ii) wave basin (3D, unconfined wave propagation). The wave height in 2D and 3D di...

Iceberg calving at outlet glaciers contributes to global sea-level rise in the context of climate change. This study investigates tsunamis generated by iceberg calving, so-called iceberg-tsunamis. Such tsunamis reached amplitudes of 50 m in the recent past and endanger human beings and coastal infrastructure. 73 unique large-scale experiments have...

Mass balance analysis of ice sheets is a key component to understand the effects of global warming. A significant component of ice sheet and shelf mass balance is iceberg calving, which can generate large tsunamis endangering human beings and coastal infrastructure. Such iceberg-tsunamis have reached amplitudes of 50 m and destroyed harbours. Calvi...

This study presents a numerical landslide-tsunami hazard assessment technique for applications in reservoirs, lakes, fjords, and the sea. This technique is illustrated with hypothetical scenarios at Es Vedrà, offshore Ibiza, although currently no evidence suggests that this island may become unstable. The two selected scenarios include two particul...

Granular slides are omnipresent in both natural and industrial contexts. Scale effects are changes in physical behaviour of a phenomenon at different geometric scales, such as between a laboratory experiment and a corresponding larger event observed in nature. These scale effects can be significant and can render models of small size inaccurate by...

Subaerial landslide-tsunamis (impulse waves) are generated by masses impacting into a water body. This type of waves has resulted in catastrophes in the recent past such as in the Vajont disaster in 1963 where a wave overtopped a dam and caused approximately 2000 casualties. The effect of the water body geometry on landslide-tsunamis is mainly inve...

A widely applied model strategy in experimental fluid dynamics is to conduct laboratory experiments at reduced scale in the Reynolds number R invariant regime to ensure that the turbulent behaviour in the field situation is correctly modelled. This study investigates R invariance and quantifies R scale effects in dissipative-type shallow-water vort...

Granular slides are common phenomena, seen in both natural and industrial contexts in a wide variety of geometric configurations and particle characteristics. Despite being ubiquitous, creating a definitive model for granular slides has proven difficult due to the dependence of a particle’s behaviour on both its location within the slide mass and t...

This review aims to improve the reliability of Froude modelling in fluid flows where both the Froude number and Reynolds number are a priori relevant. Two concepts may help to exclude significant Reynolds number scale effects under these conditions: (i) self-similarity and (ii) Reynolds number invariance. Both concepts relate herein to turbulent fl...

Printed Edition of the Special Issue Published in Journal of Marine Science and Engineering.

This article addresses subaerial landslide-tsunamis with a composite (experimental-numerical) modelling approach. A shortcoming of generic empirical equations used for hazard assessment is that they are commonly based on the two idealised water body geometries of a wave channel (2D) or a wave basin (3D). A recent systematic comparison of 2D and 3D...

Presentation about Wave energy resource at 4th CoastLab Teaching School, Wave and Tidal Energy, Porto, 17-20th January 2012

Presentation about Technology Readiness Approach for the development of WECs at 4th CoastLab Teaching School, Wave and Tidal Energy, Porto, 17-20th January 2012

Presentation about Case study Anaconda at 4th CoastLab Teaching School, Wave and Tidal Energy, Porto, 17-20th January 2012

Presentation about Model-prototype similarity at 4th CoastLab Teaching School, Wave and Tidal Energy, Porto, 17-20th January 2012

Preliminary landslide-tsunami hazard assessment is commonly based on empirical equations derived from wave channel (2D) or wave basin (3D) experiments. The far-field wave in 2D can easily be an order of magnitude larger than in 3D. The present study systematically investigates the effect of the water body geometry on the wave characteristics in the...

Subaerial landslide-tsunamis (impulse waves) are generated by mass movements such as landslides, rock falls or glacier calving interacting with a water body. Preliminary landslide-tsunami hazard assessment is commonly based on empirical equations derived from wave channel (2D) or wave basin (3D) experiments. It is crucial to select the most appropr...

The significance of the impulse product parameter P is reviewed, which is believed to be the most universal parameter for subaerial landslide tsunami (impulse wave) prediction. This semi-empirical parameter is based on the streamwise slide momentum flux component and it was refined with a multiple regression laboratory data analysis. Empirical equa...

Granular slides are ubiquitous in nature and industry though a universal model to predict granular slides is difficult to realise due to their complex and transient nature. Laboratory experiments are essential in enhancing our physical understanding of granular flows and supporting hazard mitigation. However, scale effects are a major drawback of u...

[1] Subaerial landslide-tsunamis and impulse waves are caused by mass movements impacting into a water body, and the hazards they pose have to be reliably assessed. Empirical equations developed with physical Froude model studies can be an efficient method for such predictions. The present study improves this methodology and addresses two significa...

This chapter gives an overview of the development of wave energy converters (WECs) from initial conception to commercial demonstration. The structure of the chapter follows the Technology Readiness Level (TRL) approach, as recommended by several documents for the development of WECs. An overview about the TRL approach is given in Section 8.04.1. Th...

Landslide-generated tsunami predictions are commonly based on two-dimensional (2D) wave channel or three-dimensional (3D) wave basin experiments with considerably different outcomes. It is not fully understood which idealized water body geometry applies best to a specific prototype. Hence, a physical small-scale model study has been conducted that,...

Recent seafloor mapping around volcanic islands shows that submarine landslide deposits are common and widespread. Such landslides may cause devastating tsunamis, but accurate assessment of tsunami hazard relies on understanding failure processes and sources. Here we use high-resolution geophysical data offshore from Montserrat, in the Lesser Antil...

Laboratory measurements of the performance of the Anaconda are presented, a wave energy converter comprising a submerged water-filled distensible tube aligned with the incident waves. Experiments were carried out at a scale of around 1:25 with a 250 mm diameter and 7 m long tube, constructed of rubber and fabric, terminating in a linear power take-...

The aim of the present study is to provide a rigorous analysis of the water wave modelling capabilities of the advanced multi-purpose CFD code Fluidity. This code has been developed at Imperial College London over a large number of years and ben-efits from an open source GNU license. In contrast to similar studies adopting closed-source in-house or...

Scale effects arise due to force ratios which are not identical between a model and its real-world prototype and result in deviations between the up-scaled model and prototype observations. This review article considers mechanical, Froude and Reynolds model–prototype similarities, describes scale effects for typical hydraulic flow phenomena and dis...

Subaerial landslide generated impulse waves were investigated in a prismatic wave channel. Seven governing parameters, namely the still water depth, slide impact velocity, slide thickness, bulk slide volume, bulk slide density, slide impact angle, and grain diameter, were systematically varied. The generated impulse waves are nonlinear, intermediat...

This research intends to provide a detailed data basis for numerical modelling of impulse waves. Three tests are described involving a rectangular wave channel, in which a trapezoidal ‘breakwater’ was inserted to study wave run-over. In addition, a reference test is also described, in which the breakwater was removed. Two-dimensional impulse waves...

This paper is a discussion of Sælevik et al. (2009). Their comparison between block and granular model results is described in more detail, along with a discussion of five parameters which may be in general responsible for deviations between block and granular models. New small scale physical model tests have been performed to support some of the s...

Subaerial landslide generated impulse waves were investigated in a prismatic wave channel based on Froude similitude and granular slide material. The tests included the following seven governing parameters: still water depth, slide impact velocity, slide thickness, bulk slide volume, bulk slide density, slide impact angle, and grain diameter. All g...

Anaconda is a wave energy converter consisting essentially of a closed rubber tube filled with water anchored head to the waves in the sea. Pressure variations due to external waves generate bulge waves in this tube which can be used to produce electrical power with a power take-off system at the tube stern. A test set-up was designed allowing for...

The first tests of the Anaconda wavepower device to be carried out in a wave basin revealed some shortcomings in the novel instrumentation that was required to record the response of the device in waves, and usefully capture wave power under laboratory conditions. The most valuable measurements were those of water waves radiated by propagating bulg...

Impulse waves in oceans, bays, lakes, or reservoirs are generated by landslides, rock falls, shore instabilities, snow avalanches, glacier calvings, or meteorite impacts. Examples are the 1958 Lituya Bay case in Alaska where the generated impulse wave reached a maximum run-up height of 524 m on the opposite shore or the 1963 Vaiont case in North It...

This article reviews the current knowledge of experimental parameter studies on subaerial landslide generated impulse waves. These are classified as studies in wave channels or wave basins based on block or granular slide models. All governing parameters of both wave generation and wave propagation are identified and transformed to governing dimens...

We recommend to use "Evers et al. (2019), Landslide generated impulse waves in reservoirs - Basics and computation, 2nd edition" for impulse wave or landslide-tsunami hazard assessment. The new version is based on this 1st edition, resolves some weaknesses and takes new work from the last 10 years into account. The full text of this new version is...

Hydraulic scale modelling involves scale effects. The limiting criteria for scale models of subaerial landslide generated impulse waves including solid, air, and water are discussed both based on a literature review and based on detailed two-dimensional experimentation. Seven scale series based on the Froude similitude were conducted involving the...