Completed notes of the course Part1

Pagina 1

GENERALISEDSYSTEMPROPERTIES modelsofverydifferentsystemsoftencontainpropertiesthatcan be characterised usingthe same mathematicalexpression 1-RESISTANCE-resistive property V= R. I Vi Voltageor drivingpotentialacross a resistor CEFFort - I : current that flowsthrougha resistor(measureofflow)4= R . ⊥EFFORWARAB DMechanicaldash pot. forceI appliedto theplingerit will moveat velocityvF= Rm. Rmidampingcoefficient(mechanicalresistance -AP: pressuredifferenceacross thetube DFluid(Paseuvelelaw)AP= Rg . & -Q: volumetricflow gluidviscosity -Rf : Glandresistance Rf= 2-CAPACITANCE-Storageproparty C= amount ofelectricalchangestoredm a capacitarperunt voltage q: accumulationofelectricchargedeliveredvi currentflowto thecapacitor g dt-V ==1dt Co = I dt me generalisedterms 4= 13 at CaMECHANICAL- we talk aboutcompliance(oppositeofstiffness) forceF appliedto a stringit moves at velocityv till a distancex x = F. Cm = judtF HOOKE'SLW F= K. x k= En C . complianceofthe string, I effortvariable, . flowvariable, z . accumulation DFWID ThefluidfilledbeloancomplianceIf is determinedbytheelasticityofthebaldon material, a smallercontributioncomesfrom the compressibilityofthe fluldinside N = Ap. of AV= jadt SP= 1 d AP: effortvarable a: flowvarableAV: accumulation the largevesserslike theportaare the mostcompliantones in thebody . theheartis a pulsatilepump, nota volumetricone of thecontawere stuffthe bloodflowwouldswitch on and off as the particvalveopensand closes . Butwe needthe bloodtoperfusethe organscontinuously(modulatedbytheheartbutcontinuous), so duringthe systobcphasethe conta mcreases its volumeso thatdoingthedastabcphasethe bloodflowcontinues ENERGYDISSIPATIONOR ACCUMULATION ELECTRICALSYSTEMPEUT energyis dissipatedwheneffortis appliedto produceflow - MECHANICALSUSTEMP= Fr throughthe…