Upper limit for tidal power with lateral bypass

Pelz, Peter F.; Metzler, Manuel; Schmitz, Christian; Müller, Tim M.

doi:10.1017/jfm.2020.99

Cited by 6 publications

(53 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only in the special case of a very long and at the same time shallow channel, does the wave cycle time share the same order of magnitude with the tidal cycle time T . It must therefore be treated as transient [5]. This is consistent with the findings of Garret & Cummins [6], Pelz et al [5] Bonar et al [7].…”

Section: Condition For Quasi-steady Flowsupporting

confidence: 79%

“…It must therefore be treated as transient [5]. This is consistent with the findings of Garret & Cummins [6], Pelz et al [5] Bonar et al [7].…”

Section: Condition For Quasi-steady Flowsupporting

confidence: 79%

“…In fact, as in gas dynamics, the head ratio H II /H I = h II /H I is physically more appropriate. This head ratio gives the downstream boundary condition to the flow [5].…”

Section: Condition For Quasi-steady Flowmentioning

confidence: 99%

“…The transient boundary conditions c(t) are given by the energy height H I (t) or H II (t). To give an example, Pelz et al [5] use for a tidal turbine with bypass the blockage σ as design, the turbine head H T as operation and either the downstream Froude number Fr 2 or the dimensionless water depth h 2 := h 2 /H I as boundary conditions.…”

Section: Array Optimisationmentioning

confidence: 99%

See 3 more Smart Citations

Misled by Betz and unsteady flow

Pelz

Lemmer

Schmitz³

2022

Int. J. Mar. Ene.

View full text Add to dashboard Cite

A turbine array is an adjustable flow resistanceR placed in a tidal channel. Ideally, it is designedand operated to maximise energy yield. Garrett & Cummins(2005), using optimal control theory applied to the RCelementchannel (R) and basin (C), showed: the energyextraction from the flow PT + PD is maximised when theflow rate is slowed down by a factor of 1/√3. This resultis independent of the ratio of the extracted mechanicalpower PT to the total power extraction including the powerloss PD due to the mixing of the bypass flows within theturbine field. The optimisation task for turbine arrays ismaximising PT. This objective raises two questions: ”Whatis the maximum power PT that can be extracted, and what isthe optimal design (size, topology) and operation to achievethis output?” When addressing them, the literature stilluses the Betz ‘limit’ as a reference. The work presentedhighlights two major problems. First, the Betz ’limit’ isnot a constant upper bound for open channel flow. Thisproblem has been discussed and solved by the first author(2011, 2020). Second and more importantly, the presentedpaper points out the misconception under which severalresearch studies referred to array topologies as ‘optimal’with regard to design and operation. Hereby, the presentedpaper contributes to the advancement of tidal power on anaxiomatic basis. The misleading by Betz and overvaluingof transient effects is made transparent in a scientificdiscourse.

show abstract

Section: Condition For Quasi-steady Flowsupporting

confidence: 79%

“…It must therefore be treated as transient [5]. This is consistent with the findings of Garret & Cummins [6], Pelz et al [5] Bonar et al [7].…”

Section: Condition For Quasi-steady Flowsupporting

confidence: 79%

“…In fact, as in gas dynamics, the head ratio H II /H I = h II /H I is physically more appropriate. This head ratio gives the downstream boundary condition to the flow [5].…”

Section: Condition For Quasi-steady Flowmentioning

confidence: 99%

Section: Array Optimisationmentioning

confidence: 99%

See 2 more Smart Citations

Misled by Betz and unsteady flow

Pelz

Lemmer

Schmitz³

2022

Int. J. Mar. Ene.

View full text Add to dashboard Cite

show abstract

“…This triggered the development of high temperature material. For wind power [3] and water power [31,34] we have similar upper limits independent of the system design and operation. For 'energy production' a clear asymptotic upper limit can often be given.…”

Section: As Good As It Gets-orientation Helps Mastering Uncertaintymentioning

confidence: 96%

Introduction

Pelz¹

2021

Springer Tracts in Mechanical Engineering

Self Cite

View full text Add to dashboard Cite

In this chapter, the motivation for this book is given. The analysis process of socio-technical systems based on data and models is examined from the perspective of uncertainty. The synthesis process of systems based on models and/or intuition leads to the important concepts of function and quality as well as data, model, and structural uncertainty. This forms both the foundation and the introduction to the following chapters. It is shown that the mastering of uncertainty is the key to Sustainable Systems Design. Thus, the societal need for safety and sustainability is met.

show abstract