Recent content by maistral

Um... I did this already :oldfrown: In my end, I found (and purchased) this program from doing what you mentioned: My fundamental issue is that it seems to lack information regarding most alcohols (other than methanol and ethanol), and most acids as well (not even acetic acid). That's why I...

Thanks for replying. Actually I managed to have access to NIST-REFPROP. Is there any other possible sources of data?

Hi! I would like to crowdsource where can I find a large tabulation of physical and chemical data (ie. density, enthalpy and entropy; for both single-phase and saturated phases) for different fluids; preferrably for alcohols and acids. What I'm trying to look for is something similar to...

Hi, I'm rather confused with the wording in Perry's Chemical Engineers' Handbook regarding "outer tube heated" and "inner tube heated" in double-pipe heat exchangers. Obviously both are opposites of each other, so I'd like to ask using "outer tube heated" as reference. When we say "outer tube...

Actually I am interested in both liquids and vapors. I wanted to predict thermodynamic properties of mixtures by using only standard equations of state (while I know they could bring up inaccuracies, I just wanted to know if this is 'possible' per se).

Just an update: I found this paper that actually is the same 'issue' that I am facing, though they just presented it. This paper: https://doi.org/10.1063/5.0039545 It stated that: I am having trouble understanding how the second equations have been made (second equation 4, to second...

Summary:: A little confusion on the momentum equation (I think). According to Wikipedia (I know, I just need basic resources for now), the conservative SWEs are : If I use product rules, I am supposed to get: For context, note that ρ is a constant and can be taken out (thus canceled out)...

Hi. I am well aware that if say, there are two components A and B, the ideal mixing enthalpy between those two components are: (1) hmix = zA hA + zB hB. If I want to get the real behavior of a pure component, I am also aware that; say for example, liquid enthalpy: (2) hL = Href + ∫CpigdT (from...

I finally got it! The notation was so confusing, sorry.

What does this imply? That either positive or negative will work?

Red arrows. The notes initially say that the error term is positive. After substitution of A and C which are clearly positive, the term suddenly became negative...? Is this a typo, or is there a theory behind this?

Say for example I have a dataset (X, Y) which I need to fit to the function y = Ax^2 + By + Cxy. How do I retrieve values of A, B, and C such that they can only be integers? As of now I'm doing grid search which is so taxing.

Thanks for replying. Actually I also have the same result as yours. I seem to be unable to replicate the constant step case. I, however, found this paper: Automatic selection of the initial step size for an ODE solver and taking a glance at Equation (3.3); It's weird since it actually...

I am not sure where I should be posting this; I am perfectly aware this is Taylor expansion calculus, but considering the fact that I am working with numerical ODE solutions, I posted this here. In the paper: Implementation of an Adaptive BDF2 Formula and Comparison with the MATLAB Ode15s...

No, what I mean is the variable step/variable order BDF/NDF which is typically used by programs like MATLAB. I don't quite understand why on Earth would you force the order to be lowered; I fully understand the vsriable step part but not the variable order part.