effect of gyroscopic couple on a naval ship

8/15/2019 Effect of Gyroscopic Couple on a NAVAL SHIP

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EFFECT OF GYROSCOPIC

COUPLE ON A NAVAL SHIP

Presented by –

AMBARNIL BHARDWAJ

Roll no- M-15/12

Mechn!cl "n#!neer!n#$

J%RHA& "N'IN""RIN'(%LL"'"


2/16

What is GYROSCOPIC COUPLE?

&he t)rn!n# *o*ent +h!ch o,,oses ny

chn#e o the !ncl!nt!on o the .!s o

rott!on o #yrosco,e !s no+n s

#yrosco,!c co),le0'yrosco,e - A gyroscope !s de!ce or

*es)r!n# or *!nt!n!n# or!entt!on$ bsed

on the ,r!nc!,les o n#)lr *o*ent)*0

Mechn!clly$ #yrosco,e !s s,!nn!n#

+heel or d!sc !n +h!ch the .le !s ree to

ss)*e ny or!entt!on0


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A GYROSCOPE


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5/16

Some important terms -

Act!e orce - When body *oes lon# c)red

,th +!th )n!or* l!ner eloc!ty$ orce !n the

d!rect!on o centr!,etl ccelert!on no+n s

centr!,etl orce3 hs to be ,,l!ed e.ternlly oer the

body$ so tht !t *oes lon# the re4)!red c)red ,th0&h!s e.ternl orce ,,l!ed !s no+n s ct!e orce0

Rect!e orce – When body$ !tsel$ !s *o!n# +!th

)n!or* l!ner eloc!ty lon# c!rc)lr ,th$ !t !s

s)bected to the centr!)#l orce rd!lly o)t+rds0

&h!s centr!)#l orce !s clled rect!e orce0 &he

ct!on o the rect!e orce !s to t!lt or *oe the body

lon# rd!lly o)t+rd d!rect!on0


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A.!s o s,!n – &he .!s bo)t +h!ch +heel or

d!s reoles or s,!ns !s no+n s .!s o s,!n0

A.!s o ,recess!on – &he .!s bo)t +h!ch the .!s

o s,!n t)rns !s no+n s .!s o ,recess!on0 Plne o s,!nn!n# – &he ,lne !n +h!ch +heel or

d!sc rottes !s no+n s ,lne o s,!nn!n#0

Plne o ,recess!on – &he ,lne !n +h!ch .!s o

s,!n rottes !s no+n s ,lne o ,recess!on0


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8/16


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Coupe on a %ava Ship

durin& Steerin& 6teer!n# !s the t)rn!n# o co*,lete sh!, !n c)re to+rds let or r!#ht$ +h!le !t *oes or+rd0

(ons!der the sh!, t!n# let t)rn$ nd rotor

rottes !n the cloc+!se d!rect!on +hen !e+ed

ro* the stern$ s sho+n !n !#)re0


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When the rotor o the sh!, rottes !n the cloc+!se d!rect!on

+hen !e+ed ro* the stern$ !t +!ll he !ts n#)lr

*o*ent)* ector !n the d!rect!on ox as shown

As the ship steers to the let$ the ct!e #yrosco,!c co),le +!ll

chn#e the n#)lr *o*ent)* ector ro* ox to ox′. he

ector xx′ now represents the active g!roscopic couple and is

perpendicular to ox. &h)s the ,lne o ct!e #yrosco,!c

co),le !s ,er,end!c)lr to xx′ nd !ts d!rect!on !n the .!s %7or let hnd t)rn !s cloc+!se0 &he rect!e #yrosco,!c co),le

o the s*e *#n!t)de +!ll ct !n the o,,os!te d!rect!on !0e0 !n

nt!cloc+!se d!rect!on ". &he eect o th!s rect!e #yrosco,!c

co),le !s to r!se the bo+ nd lo+er the stern0


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Notes:10 When the sh!, steers to the r!#ht )nder s!*!lr cond!t!ons s

d!sc)ssed boe$ the eect o the rect!e #yrosco,!c co),le$ +!ll be to

r!se the stern nd lo+er the bo+020 When the rotor rottes !n the nt!cloc+!se d!rect!on$ +hen !e+ed

ro* the stern nd the sh!, !s steer!n# to the let$ then the eect o

rect!e #yrosco,!c co),le +!ll be to lo+er the bo+ nd r!se the stern0

80 When the sh!, !s steer!n# to the r!#ht )nder s!*!lr cond!t!ons s

d!sc)ssed !n note 2 boe$ then the eect o rect!e #yrosco,!c co),le+!ll be to r!se the bo+ nd lo+er the stern0

90 When the rotor rottes !n the cloc+!se d!rect!on +hen !e+ed ro*

the bo+ or ore end nd the sh!, !s steer!n# to the let$ then the eect o

rect!e #yrosco,!c co),le +!ll be to r!se the stern nd lo+er the bo+0

50 When the sh!, !s steer!n# to the r!#ht )nder s!*!lr cond!t!ons sd!sc)ssed !n note 9 boe$ then the eect o rect!e #yrosco,!c co),le

+!ll be to r!se the bo+ nd lo+er the stern0

:0 &he eect o the rect!e #yrosco,!c co),le on bot ,ro,elled by

t)rb!ne t!n# let or r!#ht t)rn !s s!*!lr s d!sc)ssed boe0

t


12/16

e"t o $ros"op "Coupe on a %ava Ship

durin& Pit"hin&P!tch!n# !s the *oe*ent o co*,lete sh!, ), nd do+n !n

ert!cl ,lne bo)t trnserse .!s$ s sho+n

In th!s cse$ the trnserse .!s !s the .!s o ,recess!on0&he ,!tch!n# o the sh!, !s ss)*ed to te ,lce +!th s!*,le

hr*on!c *ot!on !0e0 the *ot!on o the .!s o s,!n bo)t

trnserse .!s !s s!*,le hr*on!c0


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When the ,!tch!n# !s ),+rd$ the eect o the rect!e

#yrosco,!c co),le$ +!ll try to *oe the sh!, to+rd str-bord0

%n the other hnd$ ! the ,!tch!n# !s do+n+rd$ the eect o the

rect!e #yrosco,!c co),le$ !s to t)rn the sh!, to+rds ,ort s!de0

Notes ;

10 &he eect o the #yrosco,!c co),le !s l+ys #!en on s,ec!!c ,os!t!on

o the .!s o s,!n i.e.+hether !t !s ,!tch!n# do+n+rds or ),+rds0

20 &he ,!tch!n# o sh!, ,rod)ces orces on the ber!n#s +h!ch ct

hor!


14/16

90 &he n#)lr ccelert!on d)r!n# ,!tch!n#$

&he n#)lr ccelert!on !s *.!*)*$ ! s!n =1t # $.

' M.!*)* n#)lr ccelert!on d)r!n# ,!tch!n#$>max # %&$"'


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T(A%) YOU*****

effect of gyroscopic couple on a naval ship

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