<abstract xmlns="http://www.w3.org/1999/xhtml">

This paper analyzes A.K. Oppenheim’s original works on the transition of deflagration to detonation and reviews them from the perspective of new numerical and experimental results recently obtained on such phenomena. Particular attention is focused on processes happening in the boundary layer of the tube walls ahead of the accelerating flame. The results of the theoretical analyses of temperature variations inside developing boundary layer are presented and compared to the temperature variation in a free stream away from the boundary layer. Analyses of temperature increase in such layers clearly indicate that the self-ignition of the mixture happens in the boundary layer ahead of the propagating flame front. New experimental results obtained recently by a research group from the A. V. Luikov Heat and Mass Transfer Institute in Minsk, Belarus, combined with previously conducted theoretical analyses and numerical simulations, show clearly and unambiguously that the origin of the “explosion in the explosion”, postulated by A. K. Oppenheim in 1966, is always responsible for the Deflagration-Detonation Transition (DDT) in gases and is located in the boundary layer ahead of the accelerating flame front.
</abstract>

The Contribution of A. K. Oppenheim to Explaining the Nature of the Initiation of Gaseous Detonation in Tubes

<abstract xmlns="http://www.w3.org/1999/xhtml">

Among the possible electric powerplants currently driving low-payload UAVs (up to around 10 kg of payload), batteries offer certain clear benefits, but for medium-payload operation such as aerotaxis and heavy-cargo transportation UAVs, battery capacity requirements restrict their usage due to high weight and volume. In light of this situation, fuel cell (FC) systems (FCS) offer clear benefits over batteries for the medium-payload UAV segment (> 50 kg). Nevertheless, studies regarding the application of FCS powerplants to this UAV segment are limited and the in-flight performance has not been clearly analysed. In order to address this knowledge gap, a feasibility analysis of these particular applications powered by FCS is performed in this study. A validated FC stack model (40 kW of maximum power) was integrated into a balance of plant to conform an FCS. As a novelty, the management of the FCS was optimized to maximize the FCS efficiency at different altitudes up to 12500 ft, so that the operation always implies the lowest H2 consumption regardless of the altitude. In parallel, an UAV numerical model was developed based on the ATLANTE vehicle and characterized by calculating the aerodynamic coefficients through CFD simulations. Then, both models were integrated into a 0D-1D modelling platform together with an energy management strategy optimizer algorithm and a suitable propeller model. With the preliminary results obtained from the FCS and UAV models, it was possible to ascertain the range and endurance of the vehicle. As a result, it was concluded that the combination of both technologies could offer a range over 600 km and an endurance over 5 h. Finally, with the integrated UAV-FCS model, a flight profile describing a medium altitude, medium endurance mission was designed and used to analyse the viability of FC-powered UAV. The results showed how UAVs powered by FCS are viable for the considered aircraft segment, providing competitive values of specific range and endurance.
</abstract>

Feasibility Study for a Fuel Cell-Powered Unmanned Aerial Vehicle with a 75 Kg Payload

<abstract xmlns="http://www.w3.org/1999/xhtml">

This article describes the development of a flight simulator module within the ADEMAO aircraft design framework to investigate the effects of novel airframe and propulsion technologies on new generations of aircraft. Methods used to develop and integrate the fight simulator into the overall design framework are described. The simulator is validated based on existing data from the Convair CV-880M and is then used to analyze an example case of a conceptual medium-range aircraft with advanced airframe technologies designed in the Sustainable and Energy-Efficient Aviation research cluster at the Institute of Aircraft Design and Lightweight Structures at the Technische Universität Braunschweig. Results show the deficiencies of the medium-range aircraft in short-period pitch and Dutch roll performance, and recommendations for modifications to the conceptual medium-range aircraft are drafted.
</abstract>

Department of Aeronautics, Faculty of engineering

Development of a Flight Simulator for Conceptual Aircraft Design and Sizing

<abstract xmlns="http://www.w3.org/1999/xhtml">

An airport authority needs accurate information about the actual amount of harmful emissions being generated within its airspace, to be able to take measures leading to their reduction. This article presents two methods for estimating the amount of these emissions from aircraft engines during the take off and landing cycle (LTO) in the airspace of a medium-sized airport: one based on the total amount of the aircraft annually operated in it, and a second, more precise, one for a specific airline annually operating at this airport. The conclusions stemming from the comparison of these methods can support the introduction of operational and technical procedures reducing harmful emissions in the airport airspace during LTO cycle.
</abstract>

Comparing Methods of Calculating Aircraft Engine Emissions of Harmful Exhaust Components During the Takeoff and Landing Cycle in the Airspace of an Airport

<abstract xmlns="http://www.w3.org/1999/xhtml">

In-service non-destructive inspection (NDI) is a very important part of the aircraft maintenance program that minimizes aircraft breakdowns due to the fracture of critical components. The eddy current (EC) NDI method is one of the most applicable methods for this purpose, due to its high sensitivity to fatigue cracks and corrosion damage in the main structural materials. In this paper, selective double differential type EC probes characterized by the enhanced possibility of detecting subsurface cracks initiated by fatigue or stress corrosion phenomena are presented. For different applications, a family of double differential type EC probes was developed with different sizes (from 5 to 33 mm) and different spatial resolutions. These types of probes are characterized by different operational frequencies in a wide frequency range (from 0.2 kHz to 1.0 MHz), high penetration depth and unique sensitivity to subsurface defects of different types (like elongated fatigue cracks or local corrosive pitting), and a high level of specific noise suppression concerned with the scanning inspection procedures. The EC probes proposed were investigated as effective tools for characteristic aircraft applications concerned with subsurface defect detection in multilayer structures, such as the detection of cracks in the second layer of a riveted two-layer structure or cracks initiated on the side surface of a multilayer structure with the suppression of the reinforcing hoop influence; the detection of subsurface defects in arc welding with a rough surface; the detection of cracks through repair patches fabricated from aluminum alloy or carbon fiber reinforced plastic, etc. These techniques create remarkable possibilities for the well-timed detection of dangerous damage without disassembling the aircraft structure or removing protective coating.
</abstract>

Eddy Current Techniques for Detecting Hidden Subsurface Defects in Multilayer Aircraft Structures

<abstract xmlns="http://www.w3.org/1999/xhtml">

This paper presents a mathematical model for a hydromechanical fuel governor pump, to be used in parametric diagnostics. The design and operation of the governor are described. The main requirements of the model are formulated, its structure is determined, corresponding to the specifics of the diagnostic task, and assumptions to make the model simpler are presented (single-dimensional flow and absence of heat exchange). The presented model consists of idealized elements with lumped parameters (such as pressure and mass consumption of the working fluid), accounting for the compressibility of the substance and the design arrangement of the governor (presence of mechanical rests, metering orifices of complex shapes, relay switchers, etc.). Equations of elements with lumped parameters, linked by hydraulic channels in one node, are presented. The model – a system of first-order differential-algebraic equations – is solved and the parameters of the governor pump are determined for different steady-state and transient operation modes. We compare our results to the requirements for the corresponding parameters outlined in the Engineering Specifications. The model is matched to the specifications by correcting setting parameters (tightening of elastic springs, areas of throttles, etc.), and a method of initial model linearization is developed. Based on the results, we conclude that our model can be used as a diagnostic algorithm for a governor pump, at the testing and development stages, during manufacturing, repair and maintenance.
</abstract>

Diagnostic Model of Aircraft Turbine Engine Governor Pump

AHEAD OF PRINT

Volume 2024 (2024): Issue 1 (March 2024)

Volume 2023 (2023): Issue 4 (December 2023)

Volume 2023 (2023): Issue 3 (September 2023)

Volume 2023 (2023): Issue 2 (June 2023)

Volume 2023 (2023): Issue 1 (March 2023)

Volume 2022 (2022): Issue 4 (December 2022)

Volume 2022 (2022): Issue 3 (September 2022)

Volume 2022 (2022): Issue 2 (June 2022)

Volume 2022 (2022): Issue 1 (March 2022)

Volume 2021 (2021): Issue 4 (December 2021)

Volume 2021 (2021): Issue 3 (September 2021)

Volume 2021 (2021): Issue 2 (June 2021)

Volume 2021 (2021): Issue 1 (March 2021)

Volume 2020 (2020): Issue 4 (December 2020)

Volume 2020 (2020): Issue 3 (September 2020)

Volume 2020 (2020): Issue 2 (June 2020)

Volume 2020 (2020): Issue 1 (March 2020)

Volume 2019 (2019): Issue 4 (December 2019)

Volume 2019 (2019): Issue 3 (September 2019)

Volume 2019 (2019): Issue 2 (June 2019)

Volume 2019 (2019): Issue 1 (March 2019)

Volume 2018 (2018): Issue 4 (December 2018)

Volume 2018 (2018): Issue 3 (September 2018)

Volume 2018 (2018): Issue 2 (June 2018)

Volume 2018 (2018): Issue 1 (March 2018)

Volume 2017 (2017): Issue 4 (December 2017)

Volume 2017 (2017): Issue 3 (September 2017)

Volume 2017 (2017): Issue 2 (June 2017)

Volume 2017 (2017): Issue 1 (March 2017)

Transactions on Aerospace Research

Aims&amp;ScopeAbout: History and MissionQuality AssuranceArchiving and IntegrityOpen Access and FeesAdvertising and MarketingPublishing Schedule AIMS &amp; SCOPE Core Focus and Article SelectionThe primary aim of Transactions on Aerospace Research is to serve as a dynamic platform for the advancement and exchange of state-of-the-art knowledge in aerospace research. The journal covers a wide range of topics in aerospace engineering, including but not limited to:  Aerodynamics and Aeroacoustics Avionics Aircraft Performance, Stability, and Control Structural Engineering Aerospace Materials Propulsion Systems Navigation and Guidance Systems Maintenance and Diagnostics Manufacturing Technologies Safety and Reliability Vibrations and Aeroelasticity Additionally, it welcomes contributions from related scientific areas intersecting with aviation and space exploration, including but not limited to the following:  Astrophysics Astronomy Remote Sensing Photogrammetry Atmospheric Sciences Materials Sciences Aviation and Space Law Aviation and Space Economy Aviation and Space Organization Aviation and Space Medicine History of Aviation and Space Technology Aerospace Communication In view of its history, Transactions on Aerospace Research has played a distinctive role in bringing the Eastern European aviation-engineering traditions to a wider global audience, and integrating them into the broader global traditions. However, the journal now has a more global reach. It continuously seeks to foster innovation and to encourage collaboration among researchers from diverse backgrounds, pushing the boundaries of what is considered possible in aerospace technology and science. By highlighting cutting-edge research and facilitating discourse on emerging trends and challenges, Transactions on Aerospace Research aims to be at the forefront of shaping the future of aerospace engineering and contributing significantly to the field's evolution. Transactions on Aerospace Research is an Open Access journal, offering increased visibility and impact for authors' work. We do not charge any article processing charges or other publication fees. This approach aligns with our mission to disseminate cutting-edge research freely and widely. ABOUT Transactions on Aerospace Research is published by the Łukasiewicz Research Network – Institute of Aviation in Warsaw. History and MissionThe Łukasiewicz Research Network – Institute of Aviation in Warsaw, originally established as the Technical Research Institute of Aviation back in 1926, has played a pivotal role in the testing and development of nearly all Polish-designed aircraft. The beginnings of the journal date back to an early series of publications known as “IBTL Reports”. After WWII, the Institute began publishing a research journal in 1956, then known as Transactions of the Institute of Aviation [Prace Instytutu Lotnictwa]. In 2018 the name was changed to the current one, Transactions on Aerospace Research – the new title reflecting our commitment to being a global platform for all scholars in aviation and space sciences. The primary aim of Transactions on Aerospace Research is to serve as a dynamic platform for the advancement and state-of-the-art knowledge in aerospace research. The journal has played a distinctive role in bringing the Eastern European aviation-engineering traditions to a wider global audience, and integrating them into the broader global traditions. However, the journal now has a more global reach. It continuously seeks to foster innovation and to encourage collaboration among researchers from diverse backgrounds, pushing the boundaries of what is considered possible in aerospace technology and science. By highlighting cutting-edge research and facilitating discourse on emerging trends and challenges, Transactions on Aerospace Research aims to be at the forefront of shaping the future of aerospace engineering and contributing significantly to the field's evolution. Under the leadership of Professor Cezary Galiński, Editor in Chief, our journal has consistently been growing in prestige and global reach. Quality AssuranceEach submission undergoes a rigorous double-blind peer-review process, ensuring the highest standards of academic excellence. We are proud to be indexed in a number of research databases, including the ICI Journals Master List and BazTech databases, highlighting our commitment to quality and accessibility in scientific publishing. Archiving and IntegrityAs a forward-looking scientific journal, we strive to ensure the longevity and integrity of our publications. We utilize the Sciendo archiving system in Portico [https://www.portico.org/] for long-term digital preservation. Additionally, our participation in the Similarity Check System guarantees the originality and trustworthiness of the content we publish. Open Access and Fees Transactions on Aerospace Research is an Open Access journal, offering increased visibility and impact for authors' work. We do not charge any article processing charges or other publication fees. This approach aligns with our mission to disseminate cutting-edge research freely and widely. The publishing costs for the journal are primarily covered by the Scientific Publications Department of the Łukasiewicz Research Network – Institute of Aviation in Warsaw, with additional funding sourced from the Polish Ministry of Education. Advertising and MarketingThe journal does not host any commercial advertising or marketing activities. Publishing ScheduleThe journal is published four times each year: in the months of March, June, September and December. WERSJA PLCELE I ZAKRESOPIS: Historia i misjaZapewnienie jakościArchiwizacja i integralnośćOtwarty dostęp i opłatyReklama i marketingHarmonogram wydawniczy CELE I ZAKRES Główny cel i zakres tematycznyCzasopismo Transactions on Aerospace Research ma za zadanie służyć jako dynamiczna platforma dla rozwoju i wymiany najnowocześniejszej wiedzy w dziedzinie badań nad lotnictwem i kosmonautyką. Czasopismo obejmuje szeroki zakres tematów z dziedziny inżynierii lotniczej i kosmicznej, w tym między innymi:  Aerodynamika i aeroakustyka Awionika Osiągi, stabilność i kontrola statków powietrznych Inżynieria strukturalna Materiały lotnicze i kosmiczne Systemy napędowe Systemy nawigacji i naprowadzania Konserwacja i diagnostyka Technologie produkcyjne Bezpieczeństwo i niezawodność Drgania i aeroelastyczność Ponadto, mile widziane są wypowiedzi z pokrewnych dziedzin naukowych, które przecinają się z lotnictwem i eksploracją kosmosu, w tym między innymi z następujących:  Astrofizyka Astronomia Teledetekcja Fotogrametria Nauki o atmosferze Nauki o materiałach Prawo lotnicze i kosmiczne Lotnictwo i gospodarka kosmiczna Organizacja lotnictwa i przestrzeni kosmicznej Medycyna lotnicza i kosmiczna Historia lotnictwa i technologii kosmicznych Komunikacja lotnicza Ze względu na swoją historię, Transactions on Aerospace Research odgrywa wyróżniającą się rolę w przybliżaniu wschodnioeuropejskich tradycji inżynierii lotniczej szerszej globalnej publiczności i integrowaniu ich z szerszymi tradycjami światowymi. Obecnie czasopismo ma jeszcze bardziej globalny zasięg. Nieustannie dąży do wspierania innowacji i zachęcania do współpracy naukowców z różnych środowisk, przesuwając granice tego, co uważa się za możliwe w technologii lotniczej i nauce. Transactions on Aerospace Research stara się być liderem w kształtowaniu przyszłości inżynierii lotniczej i kosmicznej oraz znacząco przyczyniać się do ewolucji tej dziedziny poprzez podkreślanie najnowocześniejszych badań i ułatwianie dyskusji na temat pojawiających się trendów i wyzwań. Transactions on Aerospace Research jest czasopismem Open Access. Nie pobieramy żadnych opłat za przetwarzanie artykułów ani innych opłat za publikację. Takie podejście jest zgodne z naszą misją swobodnego i szerokiego rozpowszechniania najnowszych badań. OPIS „Transactions on Aerospace Research” jest czasopismo naukowe publikowane przez Sieć Badawczą Łukasiewicz - Instytut Lotnictwa w Warszawie. Historia i misja Sieć Badawcza Łukasiewicz - Instytut Lotnictwa w Warszawie została pierwotnie założona jako Techniczne Zakłady Naukowe Lotnictwa w 1926 roku i odegrała kluczową rolę w testowaniu i rozwoju niemal wszystkich samolotów polskiej konstrukcji. Początki czasopisma sięgają wczesnej serii publikacji znanych jako „Raporty IBTL”. Po II wojnie światowej, w 1956 roku, Instytut rozpoczął wydawanie czasopisma naukowego pod nazwą „Prace Instytutu Lotnictwa”. W 2018 roku nazwa została zmieniona na obecną, czyli „Transactions on Aerospace Research", co odzwierciedla nasze zaangażowanie w bycie globalną platformą dla wszystkich naukowców zajmujących się lotnictwem i naukami kosmicznymi. Czasopismo „Transactions on Aerospace Research” ma za zadanie służyć jako dynamiczna platforma dla rozwoju i wymiany najnowszej wiedzy w dziedzinie badań lotniczych. Czasopismo odgrywa wyróżniającą się rolę w przybliżaniu wschodnioeuropejskich tradycji inżynierii lotniczej szerszej globalnej publiczności i integrowaniu ich z szerszymi tradycjami światowymi. Nieustannie dąży do wspierania innowacji i zachęcania do współpracy naukowców z różnych środowisk, przesuwając granice tego, co uważa się za możliwe w technologii lotniczej i nauce. „Transactions on Aerospace Research” stara się być liderem w kształtowaniu przyszłości inżynierii lotniczej i kosmicznej oraz znacząco przyczyniać się do ewolucji tej dziedziny poprzez podkreślanie najnowocześniejszych badań i ułatwianie dyskusji na temat pojawiających się trendów i wyzwań. Pod kierownictwem profesora Cezarego Galińskiego, redaktora naczelnego, nasze czasopismo konsekwentnie zyskuje na prestiżu i globalnym zasięgu. Na podstawie komunikatu Ministra Edukacji i Nauki z dnia 17 lipca 2023 roku za artykuły publikowane na łamach Transactions on Aerospace Research przyznawane jest 20 punktów do dorobku naukowego. Zapewnienie jakościKażda praca złożona do czasopisma przechodzi rygorystyczny proces recenzji „podwójnie ślepej”, zapewniając najwyższe standardy doskonałości akademickiej. Jesteśmy indeksowani w wielu bazach danych badawczych, w tym w bazach danych ICI Journals Master List i BazTech, co podkreśla nasze zaangażowanie w jakość i dostępność publikacji naukowych. Archiwizacja i integralnośćJako przyszłościowe czasopismo naukowe staramy się zapewnić długowieczność i integralność naszych publikacji. Korzystamy z systemu archiwizacji Sciendo w Portico [https://www.portico.org/] w celu długoterminowej ochrony zasobów cyfrowych. Ponadto nasz udział w systemie Similarity Check gwarantuje oryginalność i wiarygodność publikowanych przez nas treści. Otwarty dostęp i opłatyTransactions on Aerospace Research jest czasopismem Open Access, oferującym większą widoczność i wpływ na pracę autorów. Nie pobieramy żadnych opłat za przetwarzanie artykułów ani innych opłat za publikację. Takie podejście jest zgodne z naszą misją swobodnego i szerokiego rozpowszechniania najnowszych badań. Koszty wydawnicze czasopisma pokrywane są głównie przez Dział Wydawnictw Naukowych Sieci Badawczej Łukasiewicz – Instytutu Lotnictwa w Warszawie, a dodatkowe środki pochodzą z Ministerstwa Edukacji Narodowej. Reklama i marketingCzasopismo nie prowadzi żadnych komercyjnych działań reklamowych ani marketingowych. Harmonogram wydawniczyCzasopismo jest publikowane cztery razy w roku, w miesiącach Marzec, Czerwiec, Wrzesień i Grudzień 