In industrial applications, we can meet several projects where non-Newtonian fluids has to be convey to certain points in the system, or in a given technological step, the need for mixing or even dropping. For instance: mixing and transporting slurry from coal-fired power plants from mixing equipment to deposit site. Or we can mention pumping sludge from wastewater treatment, moving the polymer melt in the chemical industry, the yoghurt process in the food industry, creams, gels, etc. in the pharmaceutical industry. For appropriate hydrodynamic sizing of these systems, the different behavior of the flow caused by non-Newtonian rheology should be known. This can be seen, for instance, in the pressure drop in the pipeline system, in the modification of the characteristic curves of radial pumps, in the flow field of the cyclone-type mixers, or in the jet breakup of slurries. Accurate flow geometry, however, means increasing operational safety and energy efficiency, which is now a major engineering task.
Keywords: affinity laws, CFD, energy efficiency, laboratory experiments, loss coefficient, non-Newtonian fluids, pipe elements, pumps.

Flow field inside a hydrodynamic mixer

The advantages of hydrodynamic mixers are the lack of moving components or mixing elements, which reduces the risk of failure. However, the description of the flow field, the appropriate sizing is essential, eg. avoiding stagnant zones or avoiding increased residential time.

Non-Newtonian fluid jet

The disintegration or smearing of the non-Newtonian fluid jets depends largely on the rheological and flow-like characteristics of the fluid. With proper intervention, the disintegration length can be varied.

Pipe Flow CFD Simulation

For sizing of pipeline systems, it is necessary to know the hydraulic resistance of straight pipes and pipe elements, which may be significantly different from the values for Newtonian fluids in the case of non-Newtonian behavior.


CFD modelling

Computational Fluid Dynamic (CFD) models are used to determine the flow field inside pipelines, pipe fittings and hydrodynamic mixers in the case of non-Newtonian fluids.

Laboratory experiments

CFD models are validated with own lay-out or real-time measurements. We perform tests with complex systems such as for booster pumping station or slurry jet break up experiments.

Analytical approach

We use analytical methods describe the appropriate flow field, validating the measurement systems and CFD models.


  • Journal papers

    • Csizmadia Péter, Till Sára, Hős, Csaba, An experimental study on the jet breakup of Bingham plastic slurries in air, EXPERIMENTAL THERMAL AND FLUID SCIENCE 102 pp. 271-278., 8 p. (2019)

    • Csizmadia Péter, Till Sára, The Effect of Rheology Model of an Activated Sludge on to the Predicted Losses by an Elbow, PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING 62 : 4 pp. 305-311. Paper: 12348, 7 p. (2018)

    • Csizmadia Péter, Hős Csaba, CFD-based estimation and experiments on the loss coefficient for Bingham and power-law fluids through diffusers and elbows, COMPUTERS AND FLUIDS 99: pp. 116-123. (2014)

    • Csizmadia Péter, Hős Csaba János, Predicting the friction factor in straight pipes in the case of Bingham plastic and the power-law fluids by means of measurements and CFD simulation, PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING 57:(1-2) pp. 79-83. (2013)

    • Csizmadia Péter, Hős Csaba, LDV measurements of Newtonian and non-Newtonian open-surface swirling flow in a hydrodynamic mixer, PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING 57:(2) pp. 29-35. (2013)

  • Conference papers

    • Csizmadia Péter, Till Sára, Numerical investigation of loss coefficient of elbow in the case of non-Newtonian sludge, 9th IWA Eastern European YWPs Conference. Budapest, Magyarország, 2017.05.24-2017.05.27. Budapest: pp. 404-409.

    • Csizmadia Péter, Hős Csaba János, Pandula Zoltán, LDV Measurements and CFD Simulations of the Swirling Flow in a Hydrodynamic Mixer, Conference on Modelling Fluid Flow (CMFF’12): The 15th International Conference on Fluid Flow Technologies: 2012. pp. 545-551.


Péter CSIZMADIA (PhD), assistant professor, BME Faculty of Mechanical Engineering, Department of Hydrodynamic Systems