Recent content by jangseok seo

hi all, this is Entropy Rate Balance for Control Volumes. in the case of throttling process, .throttling process is irreversible process, so (S2- S1) must be greater than zero. what i want to know is to prove that (s2-s1) is greater than zero. Thank you in advance.

um... dh is zero ( dh = 0 ) so, TdS= -VdP <--> dS=-VdP/T and dP is negative. however, as fas as i know, V and T are both variables. in the case of (dH= TdS + VdP), i don't understand that 1. T and V are both constant. 2. dV is positive and generally dT is negative ( exceptionally helium has a...

dH= TdS + VdP

yes, i know the general relationship... dh, ds, dp, du, residual properties, and maxwell equation etc.

sorry, i understand what you say. what i want to know more proves this process.(entropy > 0 ). if it possible, please show me the solving process.

thank you for your helpful answer. i think that you are talking about ideal gas., right ?? if so, I would like to know about real gas . and... I should be appreciated if you would answer the question as formula or symbol.

hi all! I am learning basic thermodynamics. I already know that expansion process of fluid through a throttling valve is irreversible process. what i wonder, why this process is irreversible. as far as i know, if delta S>0 <-- irreversible process. i want to know why Entropy of expansion...