Guilherme José de Castilho

Profa. Leila

Departamento de Engenharia de Processos (DEPro)
Assistant Professor

  • B.S., Chemical Engineering, State University of Maringá, 2005.
  • M.Sc., Chemical Engineering, State University of Campinas, 2007.
  • Dr. Eng., Chemical Engineering, State University of Campinas, 2011.

Current Focus of Research
Industrial Operations and Equipment for Chemical Engineering; Fluid Dynamics of Particulate Systems; Signal and Image Processing of Multiphase Systems.

A large research effort has been directed to the development of measurement techniques aimed at obtaining knowledge about the dynamic phenomena occurring within multiphase systems such as the fluidized bed. A quantitative description of flow regimes can be obtained from time series analyses of fluctuation signals by measuring pressure (gauge or differential) or other signals, such as solids local concentration of solids (by optical or capacitance probes) . The key to such quantification is the choice of a suitable measurement method, as well as the choice of the appropriate methods for time series analysis for the interpretation of the signal fluctuations. For this purpose, there are some analyzes that can operate in the time domain (statistical analyzes - such as mean, standard deviation, correlation, etc.); in the frequency domain (Fourier spectra); or state space analysis (Chaos). The latter is used in the analysis of nonlinear time series. Deterministic Chaos Analysis, usually inserted as a tool used in signal processing of signals obtained from particulate systems, such as fluidization, refers to a set of techniques for description and characterization of nonlinear dynamic systems characterized by showing sensitivity to initial conditions. These systems are unpredictable over a long period of time even though the differential equations that represent are completely deterministic. The two main features of the chaos invariants are: (i) correlation dimension (fractal), which is a measure for the overall complexity and number of degrees of freedom of the system, and (ii): Kolmogorov entropy, which is an as the information lost in the system or degree of unpredictability.

Another field of research is related to image processing, which the PIV technique is inserted. The Particle Omage Velocimetry (PIV) is a current and promising technique for characterizing of the fluid dynamics of multiphase reactors. The use of modern digital cameras and appropriate hardware result in maps (images) of the particle velocity field in real time, providing the instantaneous velocity measurements on a cross section of the flow.

Selected Publications
  • Castilho, G. J; Cremasco, M. A. Study of gas-solids flow in a short CFB riser by statistical and chaotic deterministic analysis of optical fibre probe signals. Canadian Journal of Chemical Engineering, v. 91, p. 579-588, 2013.

  • Amaral, L. ; Castilho, G. J. ; Cremasco, M.A. Experimental Investigation of 3D Velocity by Tomographic Particle Image Velocimetry (Tomo-PIV) in a Short Riser Section. Procedia Engineering, v. 42, p. 748-754, 2012.

  • Castilho, G. J.; Cremasco, M. A. Comparison of downer and riser flows in a circulating bed by means of optical fiber probe signals measurements. In: 20th International Congress of Chemical and Process Engineering CHISA 2012.

  • Castilho, G. J.; Cremasco, M. A.; de Martin, L.; Aragon, J. M. Experimental Fluid Dynamics Study in a Fluidized Bed by Deterministic Chaos Analysis. Particulate Science and Technology, v. 29, p. 179-196, 2011.

  • Castilho, G. J., Cremasco, M. A.. Experimental Study in a Short Circulating Fluidized Bed Riser. Particulate Science and Technology, v. 27, p. 210-221, 2009.