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This study aims to numerically study the three-dimensional (3D) flow field characteristics in a conical convergent divergent (CD) nozzle with an internal strut system to describe the effect of struts on producing a side force for thrust vectoring applications.

Struts are solid bodies. When inserted into the supersonic region of the axisymmetric CD nozzle, it induces a shock wave that causes an asymmetric pressure distribution predominantly over the internal surface of the diverging wall of the C-D nozzle, creating a net side force similar to the secondary injection thrust vectoring control method. Numerical simulations were performed by solving Unsteady Reynolds Averaged Navier–Stokes equations with re-normalized group k–ϵ turbulence model. Cylindrical struts of various heights positioned at different locations in the divergent section of the nozzle were investigated at a nozzle pressure of 6.61.

Thrust vectoring angle of approximately 3.8 degrees was obtained using a single cylindrical strut with a dimensionless thrust (%) and total pressure loss of less than 2.36% and 2.67, respectively. It was shown that the thrust deflection direction could also be changed by changing the strut insertion location. A strut located at half of the diverging length produced a higher deflection per unit total pressure loss.

Using a lightweight and high-temperature resistant material, such as a strut, strut insertion-based thrust vectoring control might provide an alternative thrust vectoring method in applications where a longer period of control is needed with a reduced overall system weight.

This study describes the 3D flow field characteristics which result in side force generation by a supersonic nozzle with an internal strut.

This paper aims to review the current knowledge about the neutral component of the local interstellar medium (LISM), which due to the resonant charge exchange, photoionization and electron impact ionization processes has a profound impact on the heliosphere structure.

This work is based on the heliospheric literature review.

The summary of four major effects of neutral hydrogen atoms penetrating solar wind (SW), i.e. the disappearance of the complicated flow structure; the emergence of “hydrogen wall” in front of the heliopause (HP); decreasing distance of termination shock (TS), HP and bow shock (BS) layer from the Sun; and recently discovered by the Interstellar Boundary Explorer mission, a region of enhanced energetic neutral atom (ENA) emission seen in all sky maps as a ribbon.

In the context of constantly developing space technologies in aerospace engineering and prospective deep space missions, there is a need of general reviews about the interstellar space surroundings of the Sun and gathering the knowledge to help in theoretical, numerical and experimental investigations such as the optimization of the scientific equipment and spacecraft structure to work in specific conditions.

The survey encapsulate basic and relevant processes playing an important role in the physics of the nearest surroundings of the Sun and the latest results of numerical and experimental investigations focused on the neutral LISM component and its influence on the heliosphere, which is strongly desired in future works. Until now, not many of such reviews have been done.

PARALLEL with the quest for higher speeds in aircraft of the traditional type, there has been a remarkable advance in rocket and missile design in recent years. The German legacy of the V2 gave both East and West a long start in this development, and full advantage of this has been taken in the period of intensive research of the past ten years. Lately the possibility of space travel has made a very profound appeal to people in all spheres and this has caused the pace of research in this field to be stepped up.

This paper presents a shape optimization problem under acoustic, aerodynamic and geometric constraints. The acoustic specification concerns the generated sonic boom. The aim is to see the validity of incomplete sensitivities when a nonlinear CFD model is coupled with a nonlinear wave transport model to define pressure rise on the ground.

The purpose of the paper is to give a brief description of the new topic introduced for the first time at the EASN Conferences.

The topic concerns the heliosphere, the nearest surrounding of the Sun and thus the nearest vicinity of the Earth. The heliosphere is created due to the interaction between the solar wind and the local interstellar medium.

This paper does not include any new information about the heliosphere and only introduces a new topic to this journal. It is briefly shown how heliospheric structures are formed, what factors affect a shape of the heliosphere, what measurements are made by Ulysses, Voyager and IBEX space missions (important for the heliosphere modeling) and how obtained data are used to validate theoretical results.

To categorize the paper under one of these classifications, research paper, viewpoint, technical paper, conceptual paper, case study, literature review or general review, the authors chose a paper type, general review, as the closest category to this paper. However, it is not a purpose of this paper to provide an extensive review of the community efforts to investigate the physical processes in the vicinity of the heliosphere interface. This is mostly a status report.

As the new topic in this journal, the article introduces in detail only a small number of aspects connected with heliosphere models. Interplanetary and interstellar magnetic field structures are primarily described. Other factors are only mentioned.

This paper aims to understand the aerodynamic blockage related to near casing flow in a transonic axial compressor using numerical simulations and to design an optimum casing groove for stall margin improvement using a surrogate optimisation technique.

A blockage parameter (Ψ) is introduced to quantify blockage across the blade domain. A surrogate optimisation technique is then used to find the optimum casing groove design that minimises blockage at an axial location where the blockage is maximum at near stall conditions.

An optimised casing groove that improves the stall margin by about 1% can be found through optimisation of the blockage parameter (Ψ).

Optimising for stall margin is rather lengthy and computationally expensive, as the stall margin of a compressor will only be known once a complete compressor map is constructed. This study shows that the cost of the optimisation can be reduced by using a suitably defined blockage parameter as the optimising parameter.

This paper aims to present the development of a highly parallel finite-difference computational fluid dynamics code in generalized curvilinear coordinates system. The objectives are to handle internal and external flows in fairly complex geometries including shock waves, compressible turbulence and heat transfer.

The code is equipped with high-order discretization schemes to improve the computational accuracy of the solution algorithm. Besides, a new method to deal with the geometrical singularities, so-called domain decomposition method (DDM), is implemented. The DDM consists of using two different meshes communicating with each other, where the base mesh is Cartesian and the overlapped one a hollow cylinder.

The robustness of the present implemented code is appraised through several numerical test cases including a vortex advection, supersonic compressible flow over a cylinder, Poiseuille flow, turbulent channel and pipe flows. The results obtained here are in an excellent agreement when compared to the experimental data and the previous direct numerical simulation (DNS). As for the DDM strategy, it was successful as simulation time is clearly decreased and the connection between the two subdomains does not create spurious oscillations.

In sum, the developed solver was capable of solving, accurately and with high-precision, two- and three-dimensional compressible flows including fairly complex geometries. It is noted that the data provided by the DNS of supersonic pipe flows are not abundant in the literature and therefore will be available online for the community.

This paper aims to demonstrate the impact of interstellar (IS) magnetic field on stellar shocks existence, shape and size in the stellar wind (SW) vs interstellar medium (ISM) numerical models.

Comparison of hydrodynamics (HD) and magnetohydrodynamic (MHD) models results with or without ISM magnetic field, its intensity and ISM parameters.

ISM magnetic field facilitates formation and stabilises bow shocks around all astrophysical objects. ISM magnetic field may also be one of the reasons for a bow shock existence around the Sun.

ISM magnetic field should be implemented in MHD and future kinetic numerical models of the SW interaction with ISM plasma.

This paper presents the results of HD and MHD models of bow shocks and the importance of ISM magnetic field implementation, according to astronomical bow shock observations. The study also presents a review of the most important papers showing the numerical results of bow shock formation.

This paper describes the numerical solutions of type‐IV shock‐on‐shock interactions in hypersonic thermochemical nonequilibrium air flows around blunt bodies. The Navier‐Stokes equation solver for a chemically reacting and vibrationally relaxing gas mixture was applied to the present problem, where the concepts of the Advection Upstream Splitting Method (AUSM) and the Lower‐Upper Symmetric Gauss‐Seidel (LU‐SGS) method were basically employed along with the two‐temperature thermochemical model of Park. The aerodynamic heating with or without the shock‐on‐shock interaction to a sphere and circular cylinders are simulated for a hypersonic nonequilibrium flow. The numerical results show that typical type‐IV shock‐on‐shock interaction pattern with a supersonic jet structure is also formed in a high‐enthalpy thermochemical nonequilibrium flow, and that the contribution of convective heat flux in the translational/rotational mode to the total heat flux is dominant. Furthermore, the inherent unsteadiness of nonequilibrium type‐IV shock‐on‐shock interaction flowfield is discussed briefly.