4 - Memorial University of Newfoundland DAI

instromentation of the model alructure, then the equipment used far the
impact twb. and, [inally, tho response circuit.
5.1.1 The Wave Maker System
The wavc tank facility nt Mcmorid Uniwrsity is 58.21 m in length, 4.57 m
in width and 3.M m in depth (re Figure 5.2). However, the hydraulically
opcrakd piab typ nave gcnorator alw shown in Figure 5.2, installed b e
lhind thc wave hosrd at one cud of the tank, restricls the d ual operating
Icngth to approximntcly 54.74 m. The walls of the tankare drrinforced comn-
crelo condruclion, whilc tho wave board is fabricated from aluminum with
n water light tellan seal along its sides and bottom. Soverd lube viewing
windows are conveniently located in one ol the tank's walls, enabling visual
and photogmphie analysis of a model's mponse at surface and aubsurfaee
olovntiona.
Both regt~lar and irregular wave spectra can be generated by the transla-
tory motion of tho a~ve bard. The fotn ospabilityaf the hydraulic actuator
shown in Pigrre 5.3 (it drives the board over s0.5 rn atmke) is lpeeifiad at
48.8 kN and limits the actual operating depth to abut 2.13 m or less. As
sl~owlb in Figure 5.4, wave heights and frequencies are governed by the mo
lions of this retaalor. Blectmnic control lor the board ia provided from the
contml roam thmugh in MTS dosed-loop aem.contmlledsyskm with error
detaction nnd eompensntis~~ applied through an LVDT fedbackloop. (Refer
to Fipn: 5.5.)
Lrwatcd at tho fnr end of the tank is a parMic beach consisting of an
nlt~n~inmnfrnmo coved by rrwdol slat. and lsyaaofnylon net. Thiadevice
ia intended to absorb and diaaipate thcenag contained in the incident wave