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Analysis of institutional authors

Carbajosa, CarlosCorresponding AuthorSanz-Andres, AngelAuthorMartinez-Cava, AlejandroAuthorOgueta-Gutierrez, MikelAuthor

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July 31, 2025
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Analysis of the unsteady shock wave motion in inlet unstart processes

Publicated to: ACTA ASTRONAUTICA. 234 601-618 - 2025-09-01 234(), DOI: 10.1016/j.actaastro.2025.05.006

Authors:

Carbajosa, Carlos; Sanz-Andres, Angel; Martinez-Cava, Alejandro; Ogueta-Gutierrez, Mikel
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Affiliations

Univ Politecn Madrid, Inst Univ Ignacio Da Riva IDR UPM, Plaza Cardenal Cisneros, E-28040 Madrid, Spain - Author

Abstract

This paper is focused on the shock wave motion during inlet starting and unstarting phenomena (swallowing and expelling of shock waves) on supersonic and hypersonic diffusers, which are critical for the efficient operation of both ramjets and scramjets. The motion speed of a normal shock wave along the inlet duct during these processes is analyzed to better understand the influence of design parameters, such as the Mach number (M infinity) and contraction ratio (CR), on the speed and stability behavior of the shock wave position. A one-dimensional (1D) quasi-steady mathematical model is presented here, labeled DS2M (Duct Shock Speed Model), which allows for fast approximate calculations. This simple approach is useful for analyzing how the shock wave motion speed changes along the duct as a function of the duct geometry and operating parameters. It also allows for shock wave position stability assessment around equilibrium positions. This model is also suitable for hypersonic configurations, where the set of shock waves that appears, so-called pseudo-shock, could be appropriately replaced by an equivalent normal shock, subjected to a corrected Mach number, lower than that of the original system. In the presentation of results, both stable and unstable cases are discussed, showing how the shock wave can be swallowed or expelled depending on the evolution of the flow and duct geometry. Finally, the results obtained from the DS2M model developed here are compared with relevant published experimental data (including shock unstart experiments on two-dimensional and three-dimensional inlets with and without combustion, as well as buzz analysis in a scramjet), showing a good agreement. Difficulties concerning the comparison exercises are outlined.
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Keywords

Duct geometriesGeometryHypersonic inletHypersonic inletsHysteresisMach numberModelMotion speedNumber theoryPlasma shock wavesPseudo shockPseudo-shocPseudo-shockRamjet/scramjetRamjetsShock trainShock wave motionShock-trainShock-waveShock-wavesStabilitUnstartUnsteady shock waves

Quality index

Bibliometric impact. Analysis of the contribution and dissemination channel

The work has been published in the journal ACTA ASTRONAUTICA due to its progression and the good impact it has achieved in recent years, according to the agency WoS (JCR), it has become a reference in its field. In the year of publication of the work, 2025, it was in position 10/55, thus managing to position itself as a Q1 (Primer Cuartil), in the category Engineering, Aerospace.

Independientemente del impacto esperado determinado por el canal de difusión, es importante destacar el impacto real observado de la propia aportación.

Según las diferentes agencias de indexación, el número de citas acumuladas por esta publicación hasta la fecha 2026-04-26:

  • Open Alex: 4
  • WoS: 3
  • Scopus: 4
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Impact and social visibility

From the perspective of influence or social adoption, and based on metrics associated with mentions and interactions provided by agencies specializing in calculating the so-called "Alternative or Social Metrics," we can highlight as of 2026-04-26:

  • The use of this contribution in bookmarks, code forks, additions to favorite lists for recurrent reading, as well as general views, indicates that someone is using the publication as a basis for their current work. This may be a notable indicator of future more formal and academic citations. This claim is supported by the result of the "Capture" indicator, which yields a total of: 1 (PlumX).

It is essential to present evidence supporting full alignment with institutional principles and guidelines on Open Science and the Conservation and Dissemination of Intellectual Heritage. A clear example of this is:

  • The work has been submitted to a journal whose editorial policy allows open Open Access publication.
  • Assignment of a Handle/URN as an identifier within the deposit in the Institutional Repository: https://oa.upm.es/91135/

As a result of the publication of the work in the institutional repository, statistical usage data has been obtained that reflects its impact. In terms of dissemination, we can state that, as of

  • Views: 98
  • Downloads: 78
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Leadership analysis of institutional authors

There is a significant leadership presence as some of the institution’s authors appear as the first or last signer, detailed as follows: First Author (CARBAJOSA FERNANDEZ, CARLOS) and Last Author (OGUETA GUTIERREZ, MIKEL).

the author responsible for correspondence tasks has been CARBAJOSA FERNANDEZ, CARLOS.

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Awards linked to the item

This work is part of the project TED2021-130541B-C21, funded by MCIN/AEI/10.13039/50110001103, the European Union "NextGenerationEU"/PRTR and project PID 2022-137630OB-C21 financed by MCIN/AEI/10.13039/501100011033/FEDER, UE. The work of Carlos Carbajosa has been supported by Programa Propio de I+D+i de la Universidad Politecnica de Madrid.
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