Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Miguel Rosa Oliveira Panão Supervised by Prof. António Luis Nobre Moreira public presentation of the research work Members of Comissão de Acompanhamento de Tese Prof. José Carlos Fernandes Pereira Prof. Paulo Manuel Cadete Ferrão Prof. João Eduardo de Barros Teixeira Borges Prof. António Luis Nobre Moreira

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact DIME – ENK6-CT Title: DIrect injection spray processes MEchanisms to improve performance WP3: Fundamental studies on droplets evaporation and impingement Task 3.1 Experiments on the impingement of single droplets and polydisperse sprays on heated surfaces. Task 3.3 Fundamental studies of gasoline sprays with forced oscillations, with/without crossflow.

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Doug Baker, TECAT Engineering Inc., Plot of the Month initiative promoted by Tecplot, November % of total HC emissions due to liquid films. - Cheng et al. (1993) - 15% of injected fuel remains liquid inside combustion chamber 1.5 increase factor in HC emissions between engine cold-start and heated engine. - Meyer and Heywood (1999) -

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Fuel Spray fuel characteristics injection conditions surrounding environment injector position & orientation Breakup and Vaporization Vapor Fuel/Air Mixture DropletLiquid Film impingement adherence vaporization adherence secondary atomization vaporization secondary breakup air carry flow through solid surfaces Panão and Moreira, Experimental Characterization of an Intermittent Gasoline Spray Impinging Under Cross-Flow Conditions, Atomization and Sprays, vol. 15, , 2005.

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact PhD Program GuidelinesPresent Contribution part I part II part III «...caracterizar os mecanismos de interação entre as gotas, a superfície e o escoamento de ar na região de incidência, onde a formação de estruturas coerentes de grande escala influenciam os processos de dispersão e vaporização. (...) os resultados serão analisados à luz dos modelos físicos existentes para descrever a dinâmica de sprays incidentes.» «...os resultados obtidos nesta fase são relevantes para a optimização dos sistemas de admissão em motores multiponto.» « A formação de um filme de líquido (...) é uma questão de importância fundamental no desenvolvimento de métodos de paragem/arranque para diminuir o consumo de combustível..» «...estudo da interacção da fase dispersa com a fase contínua.» «...pretende-se desenvolver um novo método de validação e de reconstrução do sinal para um sistema PDA de duas componentes, de forma a permitir obter a velocidade do fluido num referencial solidário com as partículas.» «...caracterização completa do processo de transmissão de calor entre o spray e a superfície em condições tanto estacionárias, como transientes.» «...determinação dos coeficientes de transmissão de calor depende da interacção de vários fenómenos que ocorrem quase simultâneamente quando múltiplas gotas incidem num filme de líquido (...) e de efeitos associados à temperatura, pressão parcial do vapor, turbulência do escoamento, etc.» (in portuguese) Characterization of spray impingement under cross-flow conditions with a 2D Phase Doppler Anemometer to quantify the time-dependent fluid dynamic interactions between an impinging intermittent spray and a cross-flow. Analysis of the expected influence exerted by the cross-flow on the impingement outcome. Measurement and analysis of the two-phase flow generated by the impact of an intermittent spray on a flat disc in order to demonstrate that predicting the outcome of spray impact requires a precise knowledge of the flow characteristics in the presence of the target.. Quantification of dynamic exchanges between an impacting spray and a liquid film and analysis of its implications to the development of spray/wall interaction models. Simultaneous measurements of the spray characteristics before impact and the surface thermal behaviour. Development of a novel approach to characterize heat transfer processes in the impact of an intermittent spray on a heated surface (overall boiling curves). Simultaneous measurements of the spray characteristics and the surface thermal behaviour on the entire spray impact area. Guideline 1 Guideline 2 Guideline 3 Guideline 4 Guideline 5 Guideline 6 part I part III Task 1 Task 2 Task 3 Task 4 Task 5 Task 6 Task 7

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Free SpraySpray Impact Spray Impact With Cross-Flow consequences of spray impact secondary droplets by splash and rebound formation of a dynamic liquid film formation of wall-jet vortex decreases penetration rate less impact energy consequences of cross-flow deviates small and slower primary drops splash becomes relatively more important enhances secondary drops production Panão and Moreira, Experimental Characterization of an Intermittent Gasoline Spray Impinging Under Cross-Flow Conditions, Atomization and Sprays, vol. 15, , Spray Impact Task 1

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Mundo, Sommerfeld and Tropea (1995, 1998) dry surface Cossali, Coghe and Marengo (1997) Bai, Gosman and Rusche (2002) wetted surface Wang, Chen and Hwang (2002) Predictive Tool to Estimated Impingement Outcome Stick Spread Splash Rebound r i Task 2 Panão and Moreira, Experimental Characterization of an Intermittent Gasoline Spray Impinging Under Cross-Flow Conditions, Atomization and Sprays, vol. 15, , 2005.

Wall Effect U EdEd Improves mixing process + Increase film thickness - Toroidal Vortex Impingement of secondary droplets Cross-Flow FDFD Droplets dwell more time inside the flow Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact TTL Pulse WITH Cross-Flow WITHOUT Cross-Flow Splash Rebound Stick Splash Spread Rebound Splash Spread Rebound Splash Spread Rebound Stick Spread Rebound Stick Panão and Moreira, Experimental Characterization of an Intermittent Gasoline Spray Impinging Under Cross-Flow Conditions, Atomization and Sprays, vol. 15, , 2005.

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Free Spray Spray Impact spray solid surface + spray impacting on solid surface Panão and Moreira, Flow characteristics of spray impingement in PFI injection systems, Experiments in Fluids, available Online, 10 June Task 3

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Sivakumar and Tropea, Physics of Fluids (2001) 14: L85-L88 Cortesy of Ana Sofia Moita, MSc, drop impact = ? spray impact drop impact Panão and Moreira, Flow characteristics of spray impingement in PFI injection systems, Experiments in Fluids, available Online, 10 June Task 4

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Liquid Film – Multiple Impacts cybernetic system Task 4

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Tropea and Roisman (2000) Correlations weighted with Kinetic Energy (T&R) Correlations weighted with Surface Energy (T&R) Panão and Moreira, Flow characteristics of spray impingement in PFI injection systems, Experiments in Fluids, available Online, 10 June Tropea and Roisman, Modeling of spray impact on solid surfaces, Atomization and Sprays, vol. 10, , Liquid Film – Multiple Impacts cybernetic system number flux axial momentum flux energy flux Task 4

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Film Evaporation Vaporization/ Boiling Transition Leidenfrost

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Loureiro, Panão and Moreira, Simultaneous measurements of droplets characteristics and surface thermal behaviour to study spray cooling with pulsed sprays, 12th Int. Symp. App. Laser Tech. Fluid Mech., Lisbon, Task 5

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Nu = a Re m Pr n We p Nu = a Re m Pr n We p Ja q Ec w Arcoumanis and Chang, Experiments in Fluids, vol. 16, pp , New Correlation Moreira, Carvalho and Panão, The Effects of Fuel Impact on Mixture Preparation in SI Engines with Port Fuel Injection, 7th Int. Conf. Eng. Auto., Naples, Film Evaporation Vaporization/ Boiling TransitionLeidenfrost Task 5

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact t inj = 5 ms t inj = 10 ms Panão and Moreira, Thermo- and fluid dynamics characterization of spray cooling with pulsed sprays, Experimental Thermal and Fluid Science, in Press. spray spatial heterogeneities Task 6

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Carvalho, Panão and Moreira, The thermal interaction of pulsed sprays with hot surfaces – application to Port-Fuel Gasoline Injection systems, 20th ILASS, Orlèans, Task 6

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Carvalho, Panão and Moreira, The thermal interaction of pulsed sprays with hot surfaces – application to Port-Fuel Gasoline Injection systems, 20th ILASS, Orlèans, Task 6

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact International Journals Panão and Moreira, Thermo- and fluid dynamics characterization of spray cooling with pulsed sprays, Experimental Thermal and Fluid Science, available Online at journal website, 16 June Panão and Moreira, Flow characteristics of spray impingement in PFI injection systems, Experiments in Fluids, available Online at journal website, 10 June Panão and Moreira, Experimental characterization of an intermittent gasoline spray impinging under cross-flow conditions, Atomization and Sprays, vol. 15, pp , Panão and Moreira, Experimental study of the flow regimes resulting from the impact of an intermittent gasoline spray, Experiments in Fluids, vol. 37, pp , Panão and Moreira, Visualization and Analysis of spray impingement under cross-flow conditions, Gasoline Direct Injection Engines 2002, SP- 1719, pp , SAE International, International Conferences The thermal interaction of pulsed sprays with hot surfaces – application to Port-Fuel gasoline injection systems, Carvalho J, Panão MRO and Moreira ALN, 20th Annual Meeting of the Institute of Liquid Atomization and Spray Systems (ILASS), Orlèans, The effects of fuel impact on mixture preparation in SI engines with port fuel injection, Moreira ALN, Carvalho J and Panão MRO, 7th Int. Conf. Eng. Auto., Naples, "Time resolved heat transfer characteristics of an impinging gasoline spray", Panão MRO e Moreira ALN, 19th Annual Meeting of the Institute of Liquid Atomization and Spray Systems (ILASS), Nottingham, Simultaneous Measurements of Droplet Characteristics and Surface Thermal Behavior to Study Spray Cooling with Pulsed Sprays, H. Loureiro, M.R.O. Panão e A.L.N.Moreira, 12th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisboa, Flow Characteristics of Spray Impingement in PFI Injection Systems, M.R.O. Panão e A.L.N. Moreira, 12th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisboa, Experimental characterization of spray-wall interaction under cross-flow conditions Panão, M. R. O., Moreira, A. L. N., Proceedings of the 9th International Conference on Liquid Atomization and Spray Systems, Sorrento, 2003 Experiments on Impinging Intermittent Sprays: Dynamic Bahavior of Impact A.L.N. Moreira, A.S. Moita, M. R. Panão, 3º Congresso Luso-Moçambicano de Engenharia, Maputo, 2003 Spray Impingement on a Flat Plate under Cross-flow Conditions. M. R. Panão and A.L.N. Moreira 18th Annual Conference on Liquid Atomization and Spray Systems, Zaragosa, 2002.

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact Transmissão de Calor e Combustão (M/D) Tópicos Avançados em Mecânica dos Fluidos (M/D) Métodos Experimentais em Energia e Ambiente (L/M) Mecânica dos Fluidos Computacional (L/M) Economia, Energia e Ambiente (M/D) Experiments Complete overall boiling curves for: t inj = 10 ms; p inj = 4.5 bar; L imp = 30 mm. Simultaneous measurements of spray characteristics and surface themal behavior over the entire impact area (PFI / GDI injector) Curricula

Geometric Optics Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact scattering angle, 30º or 70º ? Visibility 30º < Visibility 70º Signal Amplitude 30º >> Signal Amplitude 70º Validation 30º > Validation 70º cross section area of measurement volume, A Roisman and Tropea, Atomization and Sprays, vol. 11, pp , Considering If L s is small relatively to the drop direction angle, then slice intersection occurs. Panão and Moreira, Thermo- and fluid dynamics characterization of spray cooling with pulsed sprays, Experimental Thermal and Fluid Science, in Press.

Experiments on Impinging Intermittent Sprays: Dynamic Behaviour of Impact