If you tighten the string more and push down on the string, it will go down less. Since deflection is less for the same force, stiffness is more. More stiffness means frequency will be more
Good presentation, difficult to understand for marine engineers as the vibration terminology and operandi is entirely different. Please send your contact to discuss with you. Regards
Good sir. Most of lectures are on vibration are only concerning one unit. It will be very helpful if u make another video onthis topic with concerning all units. If possible, a explanation of 4nos and 6nos of cylinder units.
The amplitude of vibration rises over a narrow range of rpm. The entire range over which the stress limit is exceeded, will be marked as barred range .
Sir for resonance to occur, natural frequency of system should be equal to excitation frequency. But why the timing of applied force or at what displacement position of system the force to be applied is not a criteria?
Sir it is mentioned that vibration acts in three direction axial, transverse and torsional, can u pls explain how it is transferred in these directions
To create torsional vibration there should be a varying torque. To create axial vibration a varying force in the axial direction. and similarly for lateral vibration transverse force should vary. Torsional vibration will not transfer to the foundation or the static structure. Other two will transfer through bearings.
@@vrvenkatesan5825 thanks for explanation sir, can u clarify how gas pressure acting on top of piston will act (transfer) in axial or transverse directions
@@santhoshthulasi7334 axial vibration inside the engine is due to to the has force acting on the crank pin which causes axial movement,can be prevented by fitting axial vibration damper Lateral vibration in the engine is caused by movement of connecting which causes lateral thrust on the guide shoes To counter act this force top bracing is fitted on the exhaust side of the engine
Inertia force of a rotating mass will produce only first order moment as its distance is constant from centre and it can be balanced by counter weights in reciprocating mass by formula length keeps changing always as piston moves from tdc to bdc and change in acceleration during balancing which out of three resultant forces two of them cancels out leaving the third one unbalanced. To which partial balancing of engine is done and that is how firing order of engine depends. If any thing wrong please suggest so that I can also improve
He is the best teacher I have ever known. I wish i had teachers like him in my childhood. He explains all the things in a easy way.
Very helpful for clear class 2 exam very simple explanation sir dohbt clear
great explanation
at 21:22 tighter string it should have more deflection rt? as spring stiffness is more.
If you tighten the string more and push down on the string, it will go down less. Since deflection is less for the same force, stiffness is more. More stiffness means frequency will be more
@@vrvenkatesan5825 thank you sir
Good presentation, difficult to understand for marine engineers as the vibration terminology and operandi is entirely different.
Please send your contact to discuss with you.
Regards
Good sir. Most of lectures are on vibration are only concerning one unit. It will be very helpful if u make another video onthis topic with concerning all units. If possible, a explanation of 4nos and 6nos of cylinder units.
Great class !
Sir, can you plz explain why barred range is given? Why not a particular rpm?
The amplitude of vibration rises over a narrow range of rpm. The entire range over which the stress limit is exceeded, will be marked as barred range .
Sir for resonance to occur, natural frequency of system should be equal to excitation frequency. But why the timing of applied force or at what displacement position of system the force to be applied is not a criteria?
if the two frequencies do not match, the applied force will not come at the same time every time. the vibration and the excitation cannot be in sync.
@@vrvenkatesan5825 Thank you Sir
Sir, I am an engine Cadet at Istanbul Technical University. Could you share your document as PDF?
Sir it is mentioned that vibration acts in three direction axial, transverse and torsional, can u pls explain how it is transferred in these directions
To create torsional vibration there should be a varying torque. To create axial vibration a varying force in the axial direction. and similarly for lateral vibration transverse force should vary. Torsional vibration will not transfer to the foundation or the static structure. Other two will transfer through bearings.
@@vrvenkatesan5825 thanks for explanation sir, can u clarify how gas pressure acting on top of piston will act (transfer) in axial or transverse directions
@@santhoshthulasi7334 axial vibration inside the engine is due to to the has force acting on the crank pin which causes axial movement,can be prevented by fitting axial vibration damper
Lateral vibration in the engine is caused by movement of connecting which causes lateral thrust on the guide shoes
To counter act this force top bracing is fitted on the exhaust side of the engine
Sir, the inertia forces of rotating mass and reciprocating mass generate First Order Moments or is it only due to reciprocating mass.
Inertia force of a rotating mass will produce only first order moment as its distance is constant from centre and it can be balanced by counter weights in reciprocating mass by formula length keeps changing always as piston moves from tdc to bdc and change in acceleration during balancing which out of three resultant forces two of them cancels out leaving the third one unbalanced. To which partial balancing of engine is done and that is how firing order of engine depends. If any thing wrong please suggest so that I can also improve
Do MAN know, you used their picture for the Thumpnail?