Hrvatske vode
 
Spektralni i monokromatski pristup definiranju hidrodinamičkog opterećenja na vertikalne pilote
Spectral and monochromatic approach to the definition of hydrodynamic load on vertical piles

Vanja Travaš1, Nino Krvavica1

Sažetak/Abstract: 

U radu je provedena komparativna studija između hidrodinamičkih opterećenja vjetrovnih valova na cilindrične pilote dobivenih za slučaj nailaska harmonijskog vala (monokromatski pristup) i grupe valova (spektralni pristup). U svrhu kvantifikacije opterećenja koristila se Morisonova jednadžba te se sukladno navedenom razmatranja odnose na hidraulički transparentne pilote. Spektralni pristup je baziran na sintetičkom generiranju relevantnih kinematičkih veličina iz usvojene funkcije gustoće spektra valova. Metodologija uključuje višefaznu narav valovanja, stohastički otklon faznih komponenti, stohastičku orijentaciju rasprostiranja faznih komponenti te funkcijsku zavisnost kinematike gibanja čestica mora obzirom na dubinu na kojoj se nalaze. Rezultirajući algoritmi za oba pristupa su implementirani u programski paket MathCAD 15. Kako bi se ukazao značaj komparativne analize, ista je provedena za slučajeve relevantnih valova u Jadranskom moru. U skladu s očito većom vjerodostojnosti kinematike gibanja mora u spektralnom pristupu, ustanovljen je raspon valnih karakteristika unutar kojih monokromatski pristup predviđa manje konzervativna opterećenja.

 

The paper presents a conducted comparative study between hydrodynamic loads of wind waves on cylindrical piles obtained for propagation of harmonic wave (monochromatic approach) and for a group of waves (spectral approach). The Morison equation was used for load quantification, and considerations are accordingly related to hydraulically transparent piles. The spectral approach is based on synthetic generation of relevant kinematic parameters from adopted spectrum density function of the waves. The methodology includes a multiphase character of undulation, stochastic variations of phase components, stochastic propagation of phase components and functional dependence of the kinematics of salt water particle motion on the depth at which they are located. The resulting algorithms for both approaches are implemented in the software package MathCAD 15. To show the significance of the comparative analysis, the same analysis was conducted for relevant waves in the Adriatic Sea. In accordance with an obviously higher reliability of the kinematics of sea motion in the spectral approach, the range of wave characteristics within which the monochromatic approach predicts less conservative loads was determined.

Kategorija: 
Pregledni članak / Review Paper
Ključne riječi/Key words: 

hidrodinamičko opterećenje, monokromatski val, Morisonova jednadžba, sintetičko generiranje površine mora, Tabainov spektar

hydrodynamic load, monochromatic wave, Morison equation, generation of synthetic sea surface, Tabain’s spectrum

Podaci o autorima/Authors affiliations: 

1Građevinski fakultet Sveučilišta u Rijeci, Radmile Matejčić 3, 51000 Rijeka, vanja.travas@gradri.hr

Literatura/References: 

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