Webinars

PERSPECTIVES ON “REFERENCE SPRAYS” FOR ALIGNING THE SPRAY COMMUNITY

Abstract: Cold-flow spray researchers have an array of diagnostic tools to extract meaningful information on spray characteristics. The efficacy of many of these tools depends heavily on calibration, alignment, and human operation. This can lead to large discrepancies in data values for seemingly identical setups between research groups. The application of experimental data to numerical models is thereby hindered due to inconsistencies in results caused by experimental error. Previously, an attempt was made to produce a “standard spray” termed the “research simplex atomizer (RSA)”. As manufacturing processes and diagnostic tools have improved, the research simplex atomizer has been revisited. In this webinar, the background behind the RSA is overviewed. In addition, example results from a new version of the RSA are presented. Such fundamental datasets captured from detailed test conditions can potentially provide benchmark data with the intention of other researchers testing the reproducibility of the results as well as validate CFD simulations. Preliminary findings between laboratories show good agreement in droplet size measurements and spray patterns. Such collaborations generate thought exercises when trying to explain differences between diagnostics intending to provide the same information about the spray. Finally, outlook for additional varieties of reference sprays is provided.

Aerodynamic Effect on Liquid Breakup

Recorded webinar:View recording

Abstract: Dr. Sallam’s presentation will examine both experimental and phenomenological analyses of liquid jet and sheet breakup, drawing inspiration from the seminal work of Prof. G.M. Faeth—under whom Dr. Sallam trained as one of his last Ph.D. students at the University of Michigan. By leveraging these methodologies, the study aims to elucidate the influence of injector geometry, liquid turbulence, and aerodynamic forces on atomization phenomena, with relevance to applications in liquid atomization, agricultural spraying, spray coating, and other industrial processes. The work employs shadowgraphy and holography to visualize and characterize flow structures, linking the resulting measurements to phenomenological theories that help quantify how aerodynamic forces drive both primary and secondary breakup mechanisms. The analysis covers the breakup regimes of liquid jets and sheets in stationary gases and in crossflow, highlighting critical Weber number thresholds and identifying the aerodynamic conditions that govern transitions between distinct breakup modes. By integrating experimental observations with robust phenomenological frameworks, this presentation provides a deeper understanding of atomization mechanisms and the dominant aerodynamic factors at play.

Towards H2ICE: Characterization of Hydrogen Injection, Mixing, and Combustion

Abstract: Hydrogen-fueled internal combustion engines (H2ICE) have great potential for future carbon-free transportation but have not yet reached production due to a number of technical challenges. One of the most important issues is the design of hydrogen injector systems that achieve rapid mixing to fuel-lean mixtures while also ensuring stable combustion without combustion anomalies such as pre-ignition and knocking. The ILASS community has been at the forefront of research on liquid injection systems and is now encouraging needed research on hydrogen injection. This presentation will provide an overview of ongoing FUELCOM4 project with KAUST and Saudi Aramco in an effort to enhance our knowledge in hydrogen injection, mixing, and combustion characteristics by utilizing high fidelity laser diagnostics and simulations. First, hydrogen jet injection and mixing characteristics are investigated in high pressure constant volume chamber experiment with accompanying simulations for validation. Jet penetration and dispersion characteristics depending on different injector configurations are examined. Recent development in advanced laser diagnostic technique to quantify the hydrogen fuel distribution is also discussed. Finally, parametric studies of the effects of jet dispersion and mixing on engine combustion characteristics are presented.

Overview of imaging diagnostics for the characterization of sprays and droplet fields

This talk provides an overview of the evolution of imaging diagnostics techniques applied to sprays and droplet fields. Sprays and particle fields have been extensively studied over the years, delivering in-depth understanding of the droplet formation processes and its evolution. Most of this knowledge was acquired by the development and application of numerous diagnostics, often made possible by the combined power of innovations in equipment and methods. Beginning with an exploration of early imaging techniques, this review traces the development of methodologies such as shadowgraphy, schlieren imaging, and holography. These foundational techniques paved the way for contemporary advanced imaging methods aiming at characterizing particle fields in high-speed flows, where the droplet field features smaller particle sizes and higher velocities. Continuing with the advancements brought up by new diagnostic technologies, we will also explore the impact that the evolution of hardware and data processing capabilities have brought to the field.

Application of CFD Spray Models to Accelerate Industrial Product Design

The industrial sector faces the formidable challenge of swiftly deploying products and services in a fiercely competitive landscape. To expedite product development, computational models have become increasingly indispensable, particularly in driving upfront design. Virtual tools are now being heavily relied upon to shorten product development timelines. The efficacy of these tools hinges upon their accuracy, turnaround time, and widespread deployment through well-vetted workflow practices. This webinar will delve into the application of CFD spray simulations for automotive combustion and electrification applications. The subject matter will elucidate how advanced models are validated and used to propel advanced research and expedite near-term product development within the nuances of an industrial environment. The webinar will feature a multitude of application use cases, showcasing the practical implementation of these cutting-edge techniques.