PROJECT DURATION:          01 June 2022 - 30 November 2024
DURATA PROIECTULUI:       01 Iunie 2022 - 30 Noiembrie 2024

PROJECT LEADER:               National Institute for Laser, Plasma and Radiation Physics, Magurele 077125, Ilfov, Romania
CONDUCATOR PROIECT:     Institutul National de Cercetare-Dezvoltare pentru Fizica Laserilor, Plasmei si Radiatiei, Magurele 077125, Ilfov, Romania

Contract value:                      1.050.000 lei

Valoare contract:                   1.050.000 lei

The research team:                PAVEL Nicolaie, PhD                         CS I

Echipa de cercetare:              GRIGORE Oana-Valeria, PhD           CS III

                                               STANCIU George, PhD                     CS III
 

                                               CROITORU Gabriela, PhD                CS

                                               BRANDUS Catalina-Alice, PhD         CS

                                               CRACIUN Alexandru, PhD student    ACS

                                               Loc vacant                                         CS III

                                               Loc vacant                                         CS

                                               Loc vacant (din ianuarie 2023)          CS

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● For its development, human society needs energy, and combustion is the major process by which this energy is obtained. On the other hand, human development has also led to awareness of the negative effects that energy production has on the environment. Consequently, various methods of improving combustion are sought for the efficient use of current resources; also, new resources are considered to be used in order to obtain clean energy. In the case of internal combustion engines, laser ignition has been seen as an alternative solution to increase efficiency and decrease specific emissions. Our research group has world-renowned results in laser ignition of gasoline-air mixtures in real car engines. Also, we recently reported the ignition of methane-air mixtures, using laser ignition at several points. On the other hand, studies and the use of hydrogen have seen a strong development in recent years. Within this project proposal the conditions for laser ignition of hydrogen-air mixtures of various concentrations and at different pressures will be determined. Spark-plug like laser devices will be used for ignition, emitting a single pulse or a train of successive pulses. Furthermore, a theoretical model for describing laser ignition in both these regimes will be developed. It is worth to mention that this topic fits within and corresponds to the European hydrogen strategy, established in April 2021 by "The Hydrogen Act".
● In this project the conditions for laser ignition of H₂-air mixtures will be investigated. The project has three main objectives, as follows.
O1. High-peak power, passively Q-switched Nd:YAG/Cr⁴⁺:YAG laser with pulse-train emission;
O2. Ignition of H₂/air mixtures in a static, constant-volume chamber;
O3. Modeling of the train-pulse laser ignition process.

1. STAGE I. July - December 2022
2. STAGE II. January - December 2023
3. STAGE III. January - November 2024
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RESULTS
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1. ETAPA I. Iunie - Decembrie 2022
- A fost determinata configuratia optica a laserului Nd:YAG/Cr⁴⁺:YAG, pentru emisia in trenuri de pulsuri.
- Laserul Nd:YAG/Cr⁴⁺:YAG realizat emite trenuri de pana la 10 pulsuri, fiecare puls cu energia de 2.5 mJ si durata de 0.9 ns. O a doua configuratie permite emisia de trenuri de pana la cinci pulsuri, fiecare puls cu energia de 3.8 mJ.
- A fost pregatita camera de ardere pentru experimentele de aprindere cu laser.
- Este in curs de realizare instalatia de reducere a presiunii si de livrare a H₂, care va permite realizarea de experimente de aprindere a amestecurilor H₂/aer.
- Au fost efectuate experimente de aprindere cu laser a amestecurilor de CH₄/aer, utilizand aprinderea intr-un punct cu un puls si cu trenuri de cate doua pulsuri laser, precum si aprinderea in patru puncte cu unul si cu trenuri de cate doua pulsuri laser. Au fost determinate presiunile maxime si timpii de ardere pentru fiecare configuratie de aprindere. S-a facut un studiu al influentei geometriei de aprinderea asupra limitelor de aprindere.
- S-au pus bazele unui model teoretic care sa descrie procesul de aprindere cu trenuri de pulsuri laser.

2.  ETAPA II. Ianuarie - Decembrie 2023

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3. ETAPA III. Ianuarie - Noiembrie 2024

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ARTICLES PUBLISHED IN ISI JOURNALS
1. C. Dumitrache, N. T. Vasile, G. Croitoru, N. Pavel, “Laser-induced ignition of methane-air mixtures by a four-beam, pulse-burst mode passively Q-switched Nd:YAG/Cr⁴⁺:YAG laser,” Results Phys. 42, 105958 (2022). https://doi.org/10.1016/j.rinp.2022.105958

CONFERENCES
1. N. T. Vasile, G. Croitoru, C. Dumitrache, and N. Pavel, ”Multi-point, pulse-train laser ignition of methane-air mixtures by a high-peak power passively Q-switched Nd:YAG/Cr⁴⁺:YAG compact laser,” 10th EPS-QEOD EUROPHOTON Conference, 28 Aug. - 2 Sept. 2022, Hannover, Germany; presentation TUE-P-1.1. EPJ Web Conf. 267, 01002 (2022), https://doi.org/10.1051/epjconf/202226701002
2. C. Dumitrache, G. Croitoru, N. Pavel, “Laser ignition of CH₄-air mixtures by a four-beam passively Q-switched Nd:YAG/Cr⁴⁺:YAG laser operating in burst mode," The 9th Tiny Integrated Laser and Laser Ignition Conference 2022, 19-21 April 2023, Pacifico Yokohama, Yokohama, Japan, presentation TILA-LIC2-02.
3. O. V. Grigore, A. Craciun, N. Pavel, “Thermal analysis of a passively Q-switched Nd:YAG/Cr⁴⁺:YAG laser with multiple-beam output," The 9th Tiny Integrated Laser and Laser Ignition Conference 2022, 19-21 April 2023, Pacifico Yokohama, Yokohama, Japan, presentation TILA-LICp-05.
4. G. Stanciu, F. Voicu, C. A. Brandus, C. E. Tihon, S. Hau, C. Gheorghe, G. Croitoru, L. Gheorghe, N. Pavel, ”Rare-earths doped Y₂O₃ laser materials,” International Conference on Crystal Growth and Epitaxy - ICCGE 2023, 30 July - 04 August, Naples, Italy; (poster presentation PS 2 - P30).

PATENT APPLICATIONS
1. N. Pavel, O.-V. Grigore, G. Croitoru, “Sistem Laser pentru Aprinderea Amestecurilor Combustibile,” cerere brevet de inventie OSIM; A/00314/21.06.2023.

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