2 - MASINAC.org

More documents

Recommendations

Info

PONAŠANJE BRODA NA TALASIMA____________________________Vertikalna sila kojom pritisak p T delujena proizvoljni element dužine broda(elementarnu traku broda), tada iznosidf( p)ζ= pTb( x)dx ≈≈ ρgA b( x) ⋅ sin( k ξ + ω t)⋅dxT T pS obzirom na ψ « 1 važi ξ ≈ xTada je∫( p)Fζ ρgAT b( x) sin( kTx ωpt)dx= ⋅ + ⋅ =L= ρgA ⎡TQC sin( ωpt) + QS cos( ωpt)⎤⎣ ζζ ⎦Q = b( x)cos k xdx , Q = b( x)sink xdxC T S Tζ∫Lζ∫LTo je ranije pretpostavljeni oblik poremećajne sileUkupna vertikalna sila izazvanaporemećajnim pritiskom p T je tadaF∫= df =( p) ( p)ζζL∫= ρgA b( x) ⋅ sin( k ξ + ω t)⋅dxT T pL( p)Fζ = Aζ ωpt+δζA = ρ gA ⋅Qζsin( )TζQarctgδ ζ=QSCζζpri čemu jeQ = ζQ + Q2 2C SζζPREDAVANJA 2009. 89
PONAŠANJE BRODA NA TALASIMA____________________________Treba razjasniti član( d )F ζ( p)U prethodnom izvođenju korišćen je poremećajnipritisak p T koji je posledica (samo i isključivo)regularnih talasa...Izrazi za ove talase su izvedeni na “praznoj” slobodnojpovršini, bez prisustva broda...Realno, brod svojim prisustvom remeti regularnetalase...Brod je prepreka o koju talasi udaraju, i na kojoj dolazido njihovog odbijanja i prelamanja – odnosno tzv.difrakcije talasa...Uticaj ovog dopunskog efekta obuhvata (difrakcioni)( d )članF ζZanemarićemo uticaj difrakcije...Ovo zanemarenje poznato je u literaturi kaohipoteza Fruda i Krilova...Uticaj difrakcije se ne zanemaruje u većinisavremenih kompjuterskih programima...M. Simonović...Vratimo se na izrazF = A sin( ω t+δ )ζ ζ p ζU specijalnom slučaju kada vodnalinija ij broda poseduje simetrijuijpramac – krma, važilo biQ = b( x)sink xdx =⋅⋅⋅= 0Sζ∫LZa uobičajene brodove zato važiQSζ QCζQ = Q + ζQ ≈ QT2 2C S Cζ ζ ζAζ≈ρgAT⋅ b ( x )coskTxdx∫LQSζarctgδ ζ= ≈0δζ≈ 0QCζPREDAVANJA 2009. 90
Page 3 and 4:
PONAŠANJE BRODA NA TALASIMA_______
Page 5 and 6:
Page 7 and 8:
Page 9:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41: PONAŠANJE BRODA NA TALASIMA_______
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
show all

2 - MASINAC.org

Create successful ePaper yourself

Delete template?

Save as template?