The Application Of (2+1)-flavor Lattice QCD Equation Of State In Relativistic Hydrodynamic Simulations

The hydrodynamic simulation is one of important tools to simulate the expansion of the fireball produced in relativistic heavy-ion collisions.It requires the QCD Equation of State(EoS)as its input.In the current literature there are various versions of QCD EoSs used in the studies of hydrodynamics.In this thesis we review the current status of QCD EoS obtained from Hadron Resonance Gas model(HRG)in the low temperature phase and from most updated lattice QCD computations in the relatively high temperature region.By using HRG we discussed the pressure contributed from strange mesons with strange numbers of±1 obtained from lattice QCD computations.Instead of considering the meson mass to be temperature independent in HRG we modified the relevant meson spectrum by using the screening masses at nonzero temperature.In this way we found the pressure is better reproduced by the modified HRG.As EoS is a very import input in hydrodynamic simulations we in'vestigate the de-pendence of hydrodynamic results on the EoS.By using the CLVisc code we computed the pseudo-rapidity distributions and transverse momentum spectra for charged hadrons with HotQCD EoS and s95p-pce EoS respectively.We found that these two observables are sensitive to the equation of states.Moreover we find the spectra mostly depend on the freeze out temperature if the EoS is fixed,and the spectra becomes flatter with lower freeze out temperatures.