Category Archives: Chemeng

Automatic generation of C++ code for process models – 3 of 3

Here we are at the last installment of this series of posts on automatic code generation, which started out as a journey to make the workflow for coding process models in C++ with the LIBPF™ library easier and less boring. … Continue reading

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Automatic generation of C++ code for process models – 2 of 3

In this part two of the series of three posts we will leverage the techniques discussed in part one (command-line C++ code generation from the JSON representation of process models with the jinja2 template engine) to make the code generation … Continue reading

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Automatic generation of C++ code for process models – 1 of 3

Coding process models in C++ with the help of LIBPF is easy (try one of our tutorials !), but it’s fair to say that it’s somewhat boring and error prone. For example if you add an integer parameter to your … Continue reading

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The RRSB particle size distribution

In the concrete and coal processing industries the RRSB (Rosin, Rammler, Sperling und Bennett) equation for interpolating PSD (Particle Size Distribution) curves is quite popular. The RRSB distribution is: D=1-exp(-(d/d’)^n) and has this appearance: The name RRSB is used in … Continue reading

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Sieve tray flooding correlation

The correlation of Fair, J. R., “How to Predict Sieve Tray Entrainment and Flooding” Petro/chem. Engr., 33 (10), pp. 45–62 (1961) also cited in Perry, Chemical Engineers Handbook 7th ed. page 14-27  can be used to predict the flooding limit … Continue reading

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The open area for triangular pitch perforated sheets

For heat exchanger tube plates and for sieve trays in columns, the triangular pitch arrangement is common. You can find ready-to-use formulas on the web to calculate the open area of a perforated sheets, such as this one on the … Continue reading

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Is open source an option for process simulation software ?

This is an updated version of the forum entry titled “Is open source appropriate at all for chemeng software ?” which was posted here 5 years ago; that forum seems abandoned nowadays, but the topic is still relevant so I … Continue reading

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Innovation in numerical analysis

Innovation does not stop in the field of numerical analysis, which lies at the heart of industrial applications of numerical simulation and modeling. In this regards the recent paper “Multifrontal Factorization of Sparse SPD Matrices on GPUs (ACM)” by T … Continue reading

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Heat transfer in falling-film boiling

The correlation of Kunz and Yerazunis (H. R. Kunz and S. Yerazunis, An Analysis of Film Condensation, Film Evaporation, and Single-Phase Heat Transfer for Liquid Prandtl Numbers From 0.001 to 10000, J. Heat Transfer / Volume 91 / Issue 3, … Continue reading

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A robust expression for the Log Mean Temperature Difference (LMTD)

The Log Mean Temperature Difference (LMTD) is a deceivingly simple expression to compute the average driving force in heat transfer: LMTD = (ΔT1 – ΔT2) / log(ΔT1 / ΔT2); The ΔT1 and ΔT2 are the temperature approaches, as in this … Continue reading

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