Insights On Liquid Jet Breakup And Spray Formation Of An Air-Assisted Atomizer: Conventional And Alternative Jet Fuel
Inês Ferrão (1), Miguel Mendes (2), Ana Sofia Moita (3), André Silva (4)
1. AEROG-LAETA, Universidade da Beira Interior, Covilhã, Portugal; IDMEC-LAETA, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal; IN+ LARSyS, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal, Covilhã, Lisboa, Portugal
2. IDMEC-LAETA, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal, Lisboa, Portugal
3. IN+ LARSyS, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal, Lisboa, Portugal
4. AEROG-LAETA, Universidade da Beira Interior, Covilhã, Portugal, Covilhã, Portugal
DOI:
Presently, it is imperative to address global environmental challenges. The concerns are related to the depletion of non-renewable fossil fuels, greenhouse gases, and pollutant emissions. The transportation sector contributes significantly to these issues. In particular, the aviation industry primarily relies on jet fuel, a fossil fuel responsible for around 2% of anthropogenic CO2 emissions. As a result, to address contemporary society environmental concerns and energy requirements, promising renewable and green energy sources are being intensively investigated, especially in air transportation. Sustainable aviation fuels (SAF), particularly biofuels, have been explored and indicated as a short-term solution to address the energy transition in the aviation sector. Implementing alternative fuels requires a deeper investigation regarding the spray dynamics. Following this, the present study explores conventional (Jet A-1) and alternative jet fuel (HVO) atomization, and the breakup length is explored in a wide range of operating conditions. The normalized mean breakup length was measured, and a correlation was proposed based on the experimental data. Additionally, the droplets released by the jet breakup are compared for both fuels in terms of diameter. Observations reveal the occurrence of jet flapping and bag breakup, affected by the air flowrate. The results also show that regardless of the fuel, increasing the momentum flux leads to a reduction in the normalized mean breakup length. An increase in the air flowrate promotes a shorter breakup length, resulting in a secondary droplet with smaller secondary droplet diameters. An empirical correlation was developed based on the fitting of the experimental data. This correlation indicates that the normalized mean breakup length exhibits a power law relation with M, which is consistent with the literature. This experimental study is essential to research on biofuels and aids in the development of new injectors and the precision of theoretical models integrated into numerical algorithms.
