INVERTEBRATES AND FLUID DYNAMICS: HOLDING ON. BOUNDARY LAYER Mainstream Velocity (U) Boundary layer thickness (99%) Boundary layer thickness (90%) Distance.

Slides:

Advertisements

Similar presentations

Aero-Hydrodynamic Characteristics

Advertisements

Lecture 8 – INTERTIDAL - ZONATION PHYSICAL FACTORS.

The Magic of… Bernoulli’s Principle. Aerodynamics is… The study of forces and the resulting motion of objects through the air.

The Magic of… Bernoulli’s Principle. Aerodynamics is… The study of forces and the resulting motion of objects through the air.

External Convection: Laminar Flat Plate

Hydrodynamics How organisms cope with the forces imposed on them by a dense and viscous medium.

..perhaps the hardest place to use Bernoulli’s equation (so don’t)

Pharos University ME 352 Fluid Mechanics II

Outline Kinetics (external) – Forces in human motion – Impulse-momentum – Mechanical work, power, & energy – Locomotion Energetics.

External Flows.

MECH 221 FLUID MECHANICS (Fall 06/07) Tutorial 9

II. Properties of Fluids. Contents 1. Definition of Fluids 2. Continuum Hypothesis 3. Density and Compressibility 4. Viscosity 5. Surface Tension 6. Vaporization.

FORCES AND FLUIDS 8 TH GRADE PHYSICAL SCIENCE. FORCES AND FLUIDS UNIT VOCABULARY LIST FLUIDPRESSURE ATMOSPHERIC PRESSUREBUOYANT FORCE DRAG FORCESURFACE.

Adaptations in birds and insects. Skeleton -Lightweight skeleton -Mostly thin and hollow bones.

CE 230-Engineering Fluid Mechanics Lecture # 4and5 Fluid properties (2)

Fluid Mechanics –For Civil Engineers is all about SMU Storing– Moving– Using ( Incompressible fluids - water) To design and manage these systems we need.

Flow Over Immersed Bodies

15. Physics of Sediment Transport William Wilcock (based in part on lectures by Jeff Parsons) OCEAN/ESS

Lecture 7 Exact solutions

Ecology of Sandy Beaches

Chapter 15: Human Movement in a Fluid Medium

The transmission of energy from an object passing through a fluid to the fluid is known as fluid resistance. The resistance of an object passing through.

Chapter:1 Fluids & Properties

Convection Prepared by: Nimesh Gajjar. CONVECTIVE HEAT TRANSFER Convection heat transfer involves fluid motion heat conduction The fluid motion enhances.

Journal P-5: Jumping Spider A small spider, less than 2 cm in diameter, spots an insect. The spider crouches and crawls slowly forward. Then and leaps,

Liquid State Liquid is one of the four fundamental states of matter and is the only state with a definite volume but no fixed shape. A liquid is made up.

1 Dissection of the Clam Venus mercenaria Modified from :

Drag Lecture 6 Chapter 3.

Illinois State University Chapter 8 ä Fluid Mechanics ä The Effects of Water and Air.

Lecture 8 – INTERTIDAL - ZONATION PHYSICAL FACTORS.

Pharos University ME 253 Fluid Mechanics II

6 Life in a Fluid Medium. CONSIDER FLUID MOVING IN STREAMLINES: Water flow can be visualized as streamlines Particles entrained in flow move with streamlines.

Introduction to Fluid Mechanics

LESSON LD04 Aerodynamics

Hard Starch Problem 13.. Introduction Work devided in four steps Achiveing effect Necessary equipment construction Measurement Theoretical model development.

Lecture 15 Soil Water (2) Soil Water Movement (1) Concept of Hydraulic Head Soil moisture Characteristics Darcy’s Law Infiltration.

Aerodynamic Forces Lift and Drag.

Biomechanical Principles of Motion through air and water

Human movement through air and water

Dynamic Forces Fig. from Warrick et al Nature.

ATM 301 Lecture #7 (sections ) Soil Water Movements – Darcy’s Law and Richards Equation.

Lecture Outline Chapter 9 College Physics, 7 th Edition Wilson / Buffa / Lou © 2010 Pearson Education, Inc.

What is Fluid????? A fluid may be liquid, vapour or gas. It has no permanent shape but takes up the shape of a containing vessel or channel or is shaped.

15. Physics of Sediment Transport William Wilcock (based in part on lectures by Jeff Parsons) OCEAN/ESS 410.

LAMINAR FLOW. A Core Concept of the HWSS is that a streamlined body passing through water generates a smooth laminar flow without creating turbulence.

ME 101: Fluids Engineering Chapter 6 ME Two Areas for Mechanical Engineers Fluid Statics –Deals with stationary objects Ships, Tanks, Dams –Common.

External Flows An internal flow is surrounded by solid boundaries that can restrict the development of its boundary layer, for example, a pipe flow. An.

Elementary Mechanics of Fluids

Boundary Layer on a Flat Plate: Blasius Solution H z from Kundu’s book Assuming displacement of streamlines is negligible →u = U = constant everywhere,

EXPERIMENT # 6 VISCOSITY. Objective: To determine the viscosity of glycerin.

Boundary Layer Correction Air enters a two-dimensional wind tunnel as shown. Because of the presence of the boundary layer, fluid will be displaced away.

FLUID MECHANICS where: At standard condition  W = 1000 kg/m 3  W = 9.81 KN/m 3.

Subject Name: FLUID MECHANICS Subject Code:10ME36B Prepared By: R Punith Department: Aeronautical Engineering Date:

Click on a lesson name to select. Section 1: Echinoderm Characteristics Section 2: Invertebrate Chordates Chapter 27 Echinoderms and Invertebrate Chordates.

INSECTS AND HYDRODYNAMICS:

5 Life in a Fluid Medium Notes for Marine Biology:

Ship Hydrodynamics - Resistance

Viscosity, Poiseuille’s Equation, Coanda Effect

Boundary layer equation:

6 Life in a Fluid Medium.

Fluid Mechanics & Hydraulics

KINEMATICS 1. A nozzle is so shaped that the velocity of flow along the centre line changes linearly from 1.5 m/s to 15 m/s in a distance of m. Determine.

External Flows An internal flow is surrounded by solid boundaries that can restrict the development of its boundary layer, for example, a pipe flow. An.

OCEAN/ESS Physics of Sediment Transport William Wilcock (based in part on lectures by Jeff Parsons)

Turbulence: Examples Turbulence Boundary Layer Separations.

Section 8, Lecture 1, Supplemental Effect of Pressure Gradients on Boundary layer • Not in Anderson.

ENERGY Energy J Kinetic Energy J Elastic potential energy J Ek Ee E

Boundary Layer Correction

Presentation transcript:

INVERTEBRATES AND FLUID DYNAMICS: HOLDING ON

BOUNDARY LAYER Mainstream Velocity (U) Boundary layer thickness (99%) Boundary layer thickness (90%) Distance from substrate Velocity

BOUNDARY LAYER Using the boundary layer – water pennies (Psephenidae)

BOUNDARY LAYER Mainstream Velocity (U) Distance from substrate Velocity

BOUNDARY LAYER Using the boundary layer – water pennies (Psephenidae)

Other stream insects Plecoptera Trichoptera Ephemeroptera

Stream animals– Strategies for holding on Baetis Rhithrogena Ancylus

Psephenus Neothremma Bibliocephala Stream animals– Strategies for holding on

Extreme Gradients – Swash Zone

Donax

Swash Surfing

Donax Density Shape Weight distribution

Density Density (10 3 kg/m 3 ) Donax Chione Mercenaria Spisula Macrocallista Divaricella Tellina Tagellus

Weight Distribution Pivot point

AnteriorPosterior Ventral Dorsal

Behaviour in a Swash Zone

WAVE STRESS a. Limitation of size Water flow 100% 90% Boundary layer

WAVE STRESS a. Limitation of size Water flow

WAVE STRESS b. Holding on – flow tolerance Flow rate (m/s) 3 0 Time to dislodge

WAVE STRESS c. Holding on - orientation Keyhole limpet

WAVE STRESS c. Holding on - orientation Water flow

WAVE STRESS c. Holding on - orientation <.5 m/s >.5 m/s Freq Orientation (º to flow)

WAVE STRESS d. Holding on - tenacity What is “tenacity”? 1. Testing holding power

WAVE STRESS d. Holding on - tenacity What is “tenacity”? 1. Testing holding power Kg required to dislodge Foot area (cm 2 ) 15

WAVE STRESS d. Holding on - tenacity What is “tenacity”? 1. Suction? Atmospheric pressure ≈ 1 kg/cm 2 Patella ≈ kg/cm 2 -can’t generate a force > atmospheric pressure - No negative pressure under foot

WAVE STRESS d. Holding on - tenacity What is “tenacity”? Patella Mucous layer

WAVE STRESS d. Holding on - tenacity What is “tenacity”? 2. Adhesion area surface tension Thickness of fluid Theoretical adhesion = 600 kg/cm 2

3. WAVE STRESS d. Holding on - tenacity What is “tenacity”? 2. Adhesion Tenacity (kg/cm 2 to detach) Weight of mucous

3. WAVE STRESS d. Holding on - tenacity What is “tenacity”? Foot rigidity

3. WAVE STRESS d. Holding on - tenacity What is “tenacity”? Foot rigidity l d

3. WAVE STRESS d. Holding on - tenacity What is “tenacity”? Foot rigidity Tenacity Flexibility High Low In field -

3. WAVE STRESS d. Holding on - tenacity What is “tenacity”? Drag FLOW Resistance to water movement depends on: 1) Size 2) Shape 3) Texture

3. WAVE STRESS d. Holding on - tenacity What is “tenacity”? Drag SideFrontRear Drag – not well correlated with density

Types of Limpets Non-MigratoryMigratory -don’t move far -often fixed and territorial -low r -low growth -move up shore -high r -high growth (need high food intake) -react to predators by clamping-flee from predators LESS FLEXIBLEMORE FLEXIBLE

A COMPROMISE OF SEVERAL FACTORS Sea Urchins - Echinoidea lunules

WHAT IS THE FUNCTION OF LUNULES? 1) Aid in burrowing 2) Removal of feces 3) Maintain a “communication” with the surface if buried 4) Maintain inclined posture 5) Feeding

Log lunule length Log test diameter p <.05 If lunules have a hydrodynamic function -they should grow with the animal isometric observed

Time to burrow Burrowing speed PluggedNot plugged 230 sec 231 sec

Flow through a sand dollar

Lift Weight

Lift Weight Burrowing to add weight

Sand Dollar reorientation - Dendraster

Adding weight – incorporate magnetite

Reducing lift and drag Skin drag – important? Pressure drag – depends on shape

Reducing lift and drag Skin drag – important? Pressure drag – depends on shape Very flat

Reducing lift and drag Skin drag – important? Pressure drag – depends on shape Rounded Area of lower pressure

How do you reduce lift Reduce pressure differential between upper and lower surfaces

Can sand dollars tell the direction of orientation? Anterior Posterior

Can sand dollars tell the direction of orientation? -inverted sand dollars – can flip over more easily with posterior edge facing upstream (i.e critical velocity to re-orient is lower) Hardy & Merz Invert. Bio 132:52 Initial orientation Final orientation (1 hr)