Novo: Alternative Liquid Fuels for Aviation Gas Turbines: Experiments and Modelling. Inicial: High Energy Density Fuels in Aviation Gas Turbines: Experiments and Modelling

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The Addition of Particles to an Alternative Jet Fuel

Publication . Ferrão, Inês; Mendes, Miguel; Moita, A. S.; Silva, André

The expansion of the research on nanoscale particles demonstrates several advantages in terms of stability and an increased surface area to volume ratio compared to micron-sized particles. Based on this, the present work explores the addition of aluminum particles in hydrotreated vegetable oil (HVO), an alternative jet fuel. To evaluate the influence of particle sizes, nano and micron particles (40 nm and 5 μm) in a particle concentration of 0.5 wt.% were stably suspended in HVO. This study evaluates droplet combustion with an initial diameter of 250 μm in a drop tube furnace under different furnace temperatures (600, 800, 1000 °C). A high magnification lens coupled with a high-speed camera provides qualitative and quantitative data regarding droplet size evolution and micro-explosions. Pure HVO and Jet A-1 were also tested for comparison purposes. The results reveal that the addition of aluminum particles enhances the alternative jet fuel combustion. Furthermore, decreasing the particle size and increasing the furnace temperature enhances the burning rate compared to the pure HVO. Pure HVO presents a burning rate nearly to 1.75 mm2/s until t/D20 = 0.35 s/mm2 at T = 1000 °C. When nanoparticles are added to HVO in a particle concentration of 0.5 wt.%, an improvement of 24% in burning rate is noticed. Conventional jet fuel and pure HVO do not present any disruptive burning phenomena. However, when aluminum particles were added to HVO, micro-explosions were detected at the end of droplet lifetime, regardless of the particle size.

2022-03-22Journal article

Open access

Experimental Investigation Of Disruptive Burning Phenomena On Nanofuel Droplets

Publication . Ferrão, Inês; Mendes, Miguel; Moita, A. S.; Silva, A. R. R.

The transport sector plays a crucial aspect in society and economic evolution. However, improper energy management has negatively impacted health and the environment. Thus, the use of sustainable and green fuels in the aeronautical industry has been implemented due to environmental concerns and the depletion of fossil fuels. The introduction of biofuels, a renewable energy source in the transportation sector, has shown advantages in terms of pollutant reduction. Recently, the addition of nanoparticles in the combustion of biofuel has been studied with the purpose of enhancing its combustion characteristics. Consequently, the present work evaluates nanofuel single droplet in a falling droplet method. In this way, the fiber suspension effect was neglected, and droplets in a size of 250 μm were evaluated. To this end, a comparison between pure biofuel and a nanofuel at two furnace temperatures (T = 800 ºC and T = 1000 ºC) was performed. The results reveal that disruptive burning phenomena occur when aluminum nanoparticles are added to the biofuel. Consequently, a micro-explosion determines the end of the droplet lifetime, mainly affected by the furnace temperature.

2022-07-11Conference object

Open access

The influence of aluminium particles in a Hydroprocessed Vegetable Oil combustion

Publication . Ferrão, Inês; Silva, A. R. R.; Moita, A. S.; Mendes, Miguel; Costa, Mário

The present work experimentally investigates single droplet combustion to understand the effect of aluminum particles when added to a biofuel. Experiments are carried out in a drop tube furnace to evaluate the influence of size and concentration of the aluminum particles. Two different sizes (40 nm and 5 μm) and two concentrations (0.5 and 1.0 wt.%) are studied at 1000 °C. The addition of aluminum particles improves biofuel combustion. Decreasing the particle size and increasing the particle concentration leads to a significant enhancement in the burning rate compared to the pure HVO. Micro-explosions are detected at the end of droplet lifetime when particles are added to biofuel.

2021-04-14Conference object

Open access

Single droplet combustion of aluminum nanoparticles added to a biofuel

Publication . Ferrão, Inês; Silva, A. R. R.; Moita, A. S.; Mendes, Miguel; Costa, Mário

The present work evaluates the evaporation and combustion of single droplets of a biofuel (HVO) added with aluminum nanoparticles (n-Al). Tests were carried out in a drop tube furnace that allows the control of the wall temperature and oxygen concentration, in which the single droplets were injected downward at the top of the furnace. Droplets with a diameter of 250 μm were generated from a commercial droplet generator. Experiments were conducted with two particle sizes (40 nm and 70 nm) and two particle concentrations (0.5 wt.% and 1.0 wt.%). The effect of the size and concentration of the aluminum nanoparticles added to the biofuel was studied at 1100 °C. Detailed measurements, namely the temporal evolution of the droplet size and burning rate, were analyzed post-processing images. The combustion of aluminum nanoparticles added to a biofuel reveals micro-explosions, a disruptive burning phenomenon that appears at the end of the droplet lifetime, which is greatly influenced by the particle concentration.

2020-10-23Conference object

Open access

Influence of aluminum nanoparticles in alternative fuel: Single droplet combustion experiments and modeling

Publication . Ferrão, Inês; Mendes, Tomás; Mendes, Miguel; Moita, A. S.; Silva, A. R. R.

In this work, the effect of adding aluminum nanoparticles on hydrotreated vegetable oil was investigated experimentally and numerically in terms of nanofuel stability and single droplet combustion. The purpose is to understand the phenomena related to isolated droplet combustion when metallic particles are added to a liquid biofuel. Falling droplet combustion experiments were conducted in a drop tube furnace at two different furnace temperatures (800 C and 1000 C) using a high-speed camera coupled with a high magnification lens to investigate the droplet size evolution as disruptive burning phenomena. In numerical terms, a simplified macroscopic model was developed to predict the burning behavior of isolated nanofuel droplets, considering hexadecane as a surrogate fuel for the biofuel. The results reveal that adding nanoparticles resulted in a departure from the -law. Moreover, an increase in the overall droplet burning rate was observed, and according to the numerical results, nanoparticle radiation absorption is the responsible mechanism. Micro-explosions occurred for all nanofuels, and this disruptive burning behavior substantially influenced the droplet lifetime.

2024-09-07Journal article

Open access