Calibrating Of Pipe Resistance Coefficient Based On The Growth Model Of Corrosion Scales

Kinetics of corrosion scales is studied in this paper,then the models of depositingfrom suspended particles,corrosion in pipe,germinating of microbe and biofilms arefirstly built;The relationship between corrosion scales and pipe resistance coefficient isanalyzed and the calibrating function of pipe resistance coefficient based on therelationship is also firstly built,simultaneously,what the function is verified withapplication of an typical example through Matlab and PSO shows correction errorsarrive at presumed accuracy.Some prime conclusions are the following:â‘ Parciles move under turbulent diffusion and turbophoresis,particles are affectedby the Magnus force（Fm） and the Saffman（Fs） force except gravitational setting（Fg）when the linear or angular velocity exist some differences between particles and fluidaround them.Particles would deposit at the bottom of pipe when they are affectedmainly by Fg.While particles would deposit around pipe wall under the synergy of Fmand Fs,otherwise three results are obtained:particles would deposit around pipe wall ifFm>Fs;particles would suspend in bulk water if Fs> Fmand Fs>Fg;particles would depositat the bottom Fm<Fs<Fg.â‘¡Analysing the kinetics of corrosion resulted from non-microbe in the term ofcurrent and voltage of electrode reaction,corrosion velocity equals to current at themaximum diffusion,it is v₁=4kcFD^2/3（?）^1/6。③Aanlysing the kenitcs of corrosion resulted from microbe in the term of theconservation of energy and matter,corrosion velocity is v₂=dL/dt=d/dt〔p₀/（?）p_G·ε_M/（?）ε_G φ_L〕④The net growth rate function of biofilms is inferred.The net growth rate=thegrowth rate of biofims-mortality of biofilms-shed rate+deposit rate.The growth ratemeans the rate of BDOC is absorbed and transformed;Mortality means nature mortalityand mortality by chlorination while nature mortality resultes from natural decay andprey by protozoan which can be ignored under assumption;Shed rate means biofilms isshedded-off under the shear force;Deposit rate means suspended microbe is deposited atthe pipe’s wall.⑤Relative roughness factor in the calibrating function of pipe resistancecoefficient with practicability around is improved with the depth of corrosion scalesthrough studying.â‘¥The point pipe resistance coefficient is mainly affected by corrosion scales which relates with pipe resistance coefficient is testified through Matlab and PSO in antypical exmple,and conclusion shows the values calculated by the function are similar tothe values calibrated and correction errors arrive at presumed accuracy,more importantis that the ratio correction errors locates in15%account for59%in the term of all piperesistance coefficient needed calibrated.