# Wave energy creation with quadruplets on ?

**URL:** <https://opentelemac.org/forum/t/wave-energy-creation-with-quadruplets-on/6675>\
**Category:** TOMAWAC\
**Created:** [November 26, 2021, 6:25pm UTC](https://opentelemac.org/forum/t/wave-energy-creation-with-quadruplets-on/6675 "2021-11-26T18:25:11Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![user\_8512](https://opentelemac.org/forum/letter_avatar_proxy/v4/letter/u/45deac/32.png) [@user\_8512](https://opentelemac.org/forum/u/user_8512)\
**Post date:** [November 26, 2021, 6:25pm UTC](https://opentelemac.org/forum/t/wave-energy-creation-with-quadruplets-on/6675/1 "2021-11-26T18:25:11Z")

</div>

Dear [name removed],

A very simple question related to sea state propagation in deep water in the Comoros with [name removed] (v7p3 here).

We propagated a NW sea state through the archipelago (depth about 1000-4000m) considering or not quadruplets (no wind input, no white-capping).

When quads are off, the 6.6m-11s JONSWAP boundary spectrum is correctly transferred to the coastal areas.

When quads are on, an increased SWH (+17%) is obtained along the boundary.

In both cases, the results are close to stationary (\>12h).

See attached figures.

This is a little surprising because quadruplets are only supposed to redistribute energy within the spectrum, not to create it.

Does anyone have an idea of why this is occurring?

Thanks in advance.

JBS.

 ![comores_no-quads_2.png](https://opentelemac.org/uploads/default/original/2X/0/053dfaad172f2990d17f0f858d27f9f886724e18.png)

 ![comores_with-quads_2.png](https://opentelemac.org/uploads/default/original/2X/6/63dbd9160c490b30830cc06614685885d3797870.png)

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<div class="post-metadata">

**Author:** ![user\_8512](https://opentelemac.org/forum/letter_avatar_proxy/v4/letter/u/45deac/32.png) [@user\_8512](https://opentelemac.org/forum/u/user_8512)\
**Post date:** [November 26, 2021, 6:58pm UTC](https://opentelemac.org/forum/t/wave-energy-creation-with-quadruplets-on/6675/2 "2021-11-26T18:58:20Z")

</div>

Main features of the .cas file (in [group removed], sorry):

```auto
FREQUENCE MINIMALE = 0.04

RAISON FREQUENTIELLE = 1.10

NOMBRE DE FREQUENCES = 35

NOMBRE DE DIRECTIONS = 24

PAS DE TEMPS = 5

TYPE DE SPECTRE DIRECTIONNEL AUX LIMITES = 6

HAUTEUR SIGNIFICATIVE AUX LIMITES = 6.6 		

FREQUENCE DE PIC AUX LIMITES = 0.[phone removed]

FACTEUR DE PIC AUX LIMITES = 2.0

FONCTION DE REPARTITION ANGULAIRE AUX LIMITES = 3

FACTEUR DE PONDERATION POUR FRA AUX LIMITES = 1.0

DIRECTION PRINCIPALE 1 AUX LIMITES = 225            	

ETALEMENT DIRECTIONNEL 1 AUX LIMITES = 25

PRISE EN COMPTE DES TERMES SOURCES = OUI

DISSIPATION PAR MOUTONNEMENT = 0 

DISSIPATION PAR FROTTEMENT SUR LE FOND = 1

TRANSFERTS NON LINEAIRES INTER-FREQUENCES = 0 

TRANSFERTS ENTRE TRIPLETS DE FREQUENCES = 1 

DISSIPATION PAR DEFERLEMENT = 1 

NOMBRE DE SOUS-PAS DE TEMPS POUR LE DEFERLEMENT = 4

```