Transcript SMS 491: Physical solutions to every

SMS 491: Physical solutions to
every-day problems in aquatic
sciences
• Instructors: P. Jumars and E. Boss
•
Questions  sweets
• Office hours: upon appointment
• www.marine.maine.edu/~eboss/classes/sms_491_2003/
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SMS 491: Physical solutions to
every-day problems in aquatic
sciences
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• Some important concepts from last week:
– No-slip
– Treatment of fluid as Continuum
– Viscosity
• Simulation of molecules
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Temperature and molecular motion
Velocity of boundary and molecular motion
Exchange of momentum between molecules
Propagation of momentum within the molecular cloud
SMS 491: Physical solutions to
every-day problems in aquatic
sciences
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• Mass, volume and density.
– In fluids we often cannot follow a coherent mass.
• Continuity (incompressible flows):
•Mass flux: rVA [Kg/sec], AV
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SMS 491: Physical solutions to
every-day problems in aquatic
sciences
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• Newton’s laws of motion:
– Without force a body will continue its motion
– d(momentum)/dt=Force
– When a body 1 applies a force on body 2 an equal and
opposite force is applied on body 1.
• Momentum=mV
• Momentum flux=mass flux*V=
rV2A [Kgm/sec2], AV
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SMS 491: Physical solutions to
every-day problems in aquatic
sciences
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• Pressure and stress:
– Force per unit area
– Sharp vs. blunt objects
– Within a fluid pressure is while  to the
*
container’s walls.
– Hydrostatic pressure: the weight (divided by
A) of the fluid aboveMg/A=rgh (for constant r)
Problem solving in class
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SMS 491: Physical solutions to
every-day problems in aquatic
sciences
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Application: the hydraulic press
Figure from: http://hyperphysics.phy-astr.gsu.edu/hbase/pasc.html#pp
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SMS 491: Physical solutions to
every-day problems in aquatic
sciences
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