Comparison of Experimental and Numerical Model Results of Oscillating Water Column System Under Regular Wave Conditions

Abstract

Wave energy has attracted significant attention because of its non-polluting nature, environment friendliness, low operational cost and simple maintenance procedures compared to other clean energy sources. In this study, it was attempted to optimize an oscillating water column (OWC) wave energy converter, which is constructed on a shoreline. This study proposed numerical and physical models for the optimization of the OWC-type wave energy converters. Sixty-four experimental sets were carried out by a piston-type wave maker in order to investigate the influence of wave parameters, water depth and geometry of coastal structures on the efficiency of the system. A numerical model of the experimental model sets of the OWC system was performed by a software called Flow 3D. Intersection with a water–air in the software for the determination of the free surface of a volume of fluid method is used. Kε turbulence model was used for turbulent model. The drag coefficient, surface roughness, pipe roughness and surface tension were used for calibration. It is observed that the numerical model results follow the experimental model results. The numerical and the experimental model results were compared with each other by taking into consideration the mean squared error, coefficient of determination (R2) and Nash–Sutcliffe efficiency (NSE) as performance evaluation criteria. According to the test results, the NSE value was obtained to be 0.97 and this value also shows very good agreement between numerical results and experimental results. The experimental results showed that wave parameters are strongly related to the outflow of air from the chamber, whereas the slope angle of the chamber is inversely related. Considering different water depths, the various wave series and angle of the chamber, maximum efficiency of OWC was obtained at 50 cm, wave series No. 1 and an angle of 40°, respectively.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

Abbreviations

CFD:

Computational fluid dynamics

FAVOR:

Fractional area/volume obstacle representation

LIMPET:

Land installed marine powered energy transformer

NS:

Navier–Stokes

MSE:

Mean square error

NSE:

Nash–Sutcliffe coefficient

OWC:

Oscillating water column

RANS:

Reynolds-averaged Navier–Stokes

REWEC:

Resonant wave energy converter

VOF:

Volume of fluid

A :

The cross-sectional area of the outflow air tube

A x :

Fractional area at the centers of cell faces normal to the x-direction

A y :

Fractional area at the centers of cell faces normal to the y-direction

A z :

Fractional area at the centers of cell faces normal to the z-direction

C1ε, C2ε, C3ε :

Constant values

D :

Diameter of air outflow tube

Diff:

Diffusion term

d :

Water depth

E :

Mean air velocity from the results of experimental model

\(\bar{E}\) :

Mean of E values

e :

Height of opening of the OWC front wall

F :

Fraction of fluid in each cell

f x :

Viscous acceleration in x-direction

f y :

Viscous acceleration in y-direction

f z :

Viscous acceleration in z-direction

G k :

Buoyancy production term

G x :

Body accelerations in the x-direction

G y :

Body accelerations in the y-direction

G z :

Body accelerations in the z-direction

H :

Incident wave height

k :

Kinetic energy of turbulent

L :

Wavelength

N :

Mean air velocity from the results of numerical model

\(\mathop N\limits^{ - }\) :

Mean of N values

P :

Pressure

P k :

Turbulent kinetic energy production

P owc :

Power of output air

Q :

Air discharge

R 2 :

Coefficient of determination

Re :

Reynolds number

R SOR :

Mass source

T :

Wave period

t :

Time

u :

Velocity component in x-direction

V :

Velocity of air flow

v :

Velocity component in y-direction

V f :

Volumetric fluid fraction in each cell

w :

Velocity component in z-direction

X :

Front wall length of oscillating water column system

x :

Coordinate in x-direction

x max :

Downstream boundary condition

x min :

Upstream boundary condition

y :

Coordinate in y-direction

Z :

Elevation head

z :

Coordinate in z-direction (m)

z max :

Upper limit of the solution

z min :

Base wall

α :

Front wall angle of oscillating water column system

γ :

Specific weight

ΔP :

Differential pressure

ε :

Dissipation rate of turbulent kinetic energy (kε model)

µ a :

Dynamic viscosity of air

ρ :

Density

ρ a :

Density of air

ρ w :

Density of water

ω :

Specific dissipation rate of turbulent kinetic energy (k − ω model)

References

  1. Boccotti P (2007) Comparison between a U-OWC and a conventional OWC. Ocean Eng 34:799e805

    Google Scholar 

  2. Bouali B, Larbi S (2013) Contribution to the geometry optimization of an oscillating water column wave energy converter. Energy Procedia 36:565–573

    Article  Google Scholar 

  3. Brito-Melo A, Sarmento AJNA et al. (1999) A 3D boundary element code for the analysis of OWC wave power plants. In: 9th international offshore and polar engineering conference, Brest, France, May 30–June 4, 1999

  4. Clément A (1996) Dynamic non-linear response of OWC wave energy devices. In: Proceedings of the 6th international offshore and polar engineering conference, Los Angeles, California, May 26–31, 1996

  5. Dehdar-Behbahani S, Parsaie A (2016) Numerical modeling of flow pattern in dam spillway’s guide wall. Case study: Balaroud dam, Iran. Alex Eng J 55(1):467–473

    Article  Google Scholar 

  6. Dizadji N, Sajadian SE (2011) Modeling and optimization of the chamber of OWC system. Energy 36:2360–2366

    Article  Google Scholar 

  7. El Marjani A, Castro F, Rodriguez MA, Parra MT (2008) Numerical modeling in wave energy conversion systems. Energy 33(8):1246–1253

    Article  Google Scholar 

  8. Evans DV (1982) Wave-power absorption by systems of oscillating surface pressure distributions. J Fluid Mech 114:481–499

    MathSciNet  Article  Google Scholar 

  9. Flow Science Inc. (2012) Flow-3D user’s manuals. Flow Science Inc., Santa Fe, NM

    Google Scholar 

  10. Folley M, Curran R, Whittaker T (2006) Comparison of LIMPET contra-rotating wells turbine with theoretical and model test predictions. Ocean Eng 33:1056–1069

    Article  Google Scholar 

  11. Hong K, Shin SH, Hong DC, Choi HS, Hong SW (2007) Effects of shape parameters of OWC chamber in wave energy absorption. In: Proceedings of the 17th international offshore and polar engineering conference, Lisbon, Portugal, July 1–6, 2007

  12. International Energy Agency (2005) Energy statistics of non-OECD countries. 2003–2004. IEA, Paris

    Google Scholar 

  13. Josset C, Clément AH (2007) A time-domain numerical simulator for oscillating water column wave power plants. Renew Energy 32(8):1379–1402

    Article  Google Scholar 

  14. Joyce A, Pontes MT, Bettencourt J, Sarmento AJNA, Gato L, Brito-Melo A, Falcão A (1993) Wave tank testing of shoreline OWC power plant. In: Proceedingsof 1st European wave energy symposium, Edinburgh, pp 63–66

  15. Krause P, Boyle DP, Bȁse F (2005) Comparison of different efficiency criteria for hydrological model assessment. Adv Geosci 5:89–97

    Article  Google Scholar 

  16. Liu Z, Hyun BS, Hong KY (2008) Application of numerical wave tank to OWC air chamber for wave energy conversion. In: Proceedings of 18th international offshore and polar Engineering conference, Vancouver, Canada, July 6–11, 2008, p 350e6

  17. Luo Y, Nader JR, Cooper P, Zhu SP (2014) Nonlinear 2D analysis of the efficiency of fixed oscillating water column wave energy converters. Renew Energy 64:255–265

    Article  Google Scholar 

  18. Malara G, Arena F (2013) Analytical modelling of an U-oscillating water column and performance in random waves. Renew Energy 60:116–126

    Article  Google Scholar 

  19. Marjani AE, Ruiz FC, Rodriguez MA, Santos MTP (2008) Numerical modelling in wave energy conversion systems. Energy 33:1246e53

    Article  Google Scholar 

  20. Martins E, Silveira Ramos F, Carrilho L, Gato LMC, Justino PAP, Trigo L, Neumann F (2005) CEODOURO project: overall design of a OWC in the new oporto breakwater. In: 6th European wave and tidal energy conference, University of Strathclyde, Glasgow, UK, 2005, pp 273–280

  21. Morris-Thomas MT, Irvin RJ, Thiagarajan KP (2007) An investigation into the hydrodynamic efficiency of an oscillating water column. J Offshore Mech Arct Eng 129:273

    Article  Google Scholar 

  22. Nash JE, Sutcliffe JV (1970) River flow forecasting through conceptual models, part I—a discussion of principles. J Hydrol 10:282–290

    Article  Google Scholar 

  23. Parsaie A, Dehdar-Behbahani S, Haghiabi AH (2016) Numerical modeling of cavitation on spillway’s flip bucket. Front Struct Civ Eng 10(4):438–444

    Article  Google Scholar 

  24. Ramandan A, Mohamed MH, Abdien SM, Marzouk SY, El Feky A, El Baz AR (2014) Analytical investigation and experimental validation of an inverted cup float used for wave energy conversion. Energy 70(2014):539–546

    Article  Google Scholar 

  25. Sağlam M, Sulukan E, Uyar TS (2010) Wave energy and technical potential of Turkey. J Naval Sci Eng 6(2):34–50

    Google Scholar 

  26. Sarmento AJNA, Falcao AF (1985) Wave Generation by an oscillating surface pressure and its application in wave-energy extraction. J Fluid Mech 150:467–485

    Article  Google Scholar 

  27. Shore Protection Manual (1984) U.S. Army Coastal Engineering Research Center, Department of the Army, Corps of Engineers, U.S. Govt. Printing Office, Washington, DC, USA, Vol. 1

  28. Texeira P, Davyt DP, Didier E, Ramalhais R (2013) Numerical simulation of an oscillating water column based on Navier–Stokes equations. Energy 61:513–530

    Article  Google Scholar 

  29. Tindall CE, Xu M (1996) Optimizing a wells-turbine-type wave energy system. IEEE Trans Energy Convers 11:631–635

    Article  Google Scholar 

  30. Tseng RS, Wu RH, Huang CC (2000) Model study of a shoreline wave-power system. Ocean Eng 27:801e21

    Article  Google Scholar 

  31. Wang DJ, Katory M, Li YS (2002) Analytical and experimental investigation on the hydrodynamic performance of onshore wave-power devices. Ocean Eng 29(8):871–885

    Article  Google Scholar 

  32. Warner JM (1997) Wave energy conversion in a random sea. Ph.D. thesis, Technical University of Nova Scotia, Halifax, Canada

  33. Zhang Y, Zou Q-P, Greaves D (2012) Air–water two-phase flow modelling of hydrodynamic performance of an oscillating water column device. Renew Energy 41:159–170

    Article  Google Scholar 

Download references

Acknowledgements

This research was funded by TUBITAK (The Turkish National Science and Technology Foundation) under the Grant Number 112M413. The authors are grateful to TUBITAK for supporting our study.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Farrokh Mahnamfar.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mahnamfar, F., Altunkaynak, A. & Abdollahzadehmoradi, Y. Comparison of Experimental and Numerical Model Results of Oscillating Water Column System Under Regular Wave Conditions. Iran J Sci Technol Trans Civ Eng 44, 299–315 (2020). https://doi.org/10.1007/s40996-019-00259-x

Download citation

Keywords

  • Wave energy
  • Wave energy converters
  • Experimental testing
  • Numerical modeling
  • Performance evaluation criteria
  • OWC