For those ports near estuaries (e.g. Shanghai, New York, Hamburg, etc.), the change in density may be significant, this assumption is clearly not appropriate. In also trying to assess the influence of proposed cleaning technologies (ozone, UV, centrifugal separation), which are applied in transit, the density contrast

between re-injected (cleaner) water and ballast water can be neglected. However, if ballast water is cleaned by heat, the treated water is lighter than the original water. The new element of the paper involves development of a robust multizone model GPCR & G Protein inhibitor for ballast water flushing and a detailed comparison against experimental results. To understand the influence of outlet arrangements and compartment configurations on the flushing efficiency, we examine the temporal and spatial fluid exchange experimentally. The paper is structured as follows. In Section 2, we describe how we set up the mathematical model and the diagnostic tools used to interpret the results which are discussed in the context of simplified geometries; in Section 3, we apply the model on ballast tanks with different compartment configurations and outlet arrangements; in Section 4, we present the experimental

setup and methodology; in Section 5, we analyse the experimental results and compare with the model prediction; in Section 6, we conclude. The water used to flush a ballast tank is typically pumped into the tank at a rate Q~1m3/s. GKT137831 As we move farther away from the inlet nozzle, the mean flow decays quite quickly. It is important to estimate typical values as these variables determine the type of modelling approach and the validity of the experimental analogue described later. The ballast tanks in a large ship are characterised by a typical length L  =50 m, width W  h=20 m of the base and W  v=0.5 m of the vertical Tenofovir purchase region, height H  h=2 m of the horizontal region and H  v=25 m of the vertical region, and the nominal diameter of the inlet nozzle D  =0.5 m. The mean flow velocity through the nozzle is Un=4Q/(πD2)~5m/s. The flow in a ballast

tank is characterised by the Reynolds number Re=UL/νRe=UL/ν, where ν   is the kinematic viscosity of water, ν=10−6m2/s. We start using an assessment of the typical velocity and length scales in a ballast tank, where U   and L   are the characteristic velocity and lengthscale of the flow, respectively. The inlet nozzle Reynolds number is Ren=UnD/ν~106Ren=UnD/ν~106. Based on the horizontal section, Uh≥Q/(0.5πWhHh)~10−2m/s, Reh=UhHh/ν~104Reh=UhHh/ν~104. Up the riser section, Uv=Q/(LWv)~10−2m/s, so Rev=UvWv/ν~104Rev=UvWv/ν~104. Thus the flow in a ballast tank is inertially dominant so that Re is high and the flow is turbulent. The purpose of this model is to quantify how flushing efficiency varies within a tank.