Thermophysics and Aeromechanics最新文献

{"title":"Influence of surfactants on the slug flow of immiscible liquids in a curved microchannel","authors":"A. V. Kovalev,&nbsp;A. A. Yagodnitsyna,&nbsp;A. V. Bilsky","doi":"10.1134/S0869864325040079","DOIUrl":"10.1134/S0869864325040079","url":null,"abstract":"<div><p>The dynamics of a slug flow in immiscible liquids remains incompletely understood due to the complex effects of channel geometry and the properties of the working fluids. The presence of surfactants in the system further complicates the problem. This work deals with the effect of a water solution of Tween 20 surfactant on the dynamics of a slug flow in a curved microchannel. Situations with surfactant concentrations below and above the critical concentration of micelle formation are considered. Regime maps are plotted, and three regimes of water phase dispersion are identified. It is shown that increasing the surfactant concentration leads to stabilization of slug interfaces in straight sections, while the probability of slug rupture in curved sections increases due to reduced interfacial tension and intense mixing of the surfactant within the slugs. The decisive influence of the surfactant concentration relative to the critical concentration of micelle formation on the dynamics of microdroplet detachment processes in straight and curved sections of the channel is revealed.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"897 - 903"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volumetric properties of liquid rubidium–lead alloy of equiatomic composition","authors":"R. A. Khairulin,&nbsp;R. N. Abdullaev,&nbsp;S. V. Stankus","doi":"10.1134/S0869864325040158","DOIUrl":"10.1134/S0869864325040158","url":null,"abstract":"<div><p>The density and thermal expansion of a liquid rubidium–lead alloy containing 50 at. % Pb were investigated for the first time by the gamma-ray attenuation technique in the temperature range from the liquidus to ∼1000 K. It was found that the molar volume of the Rb₅₀Pb₅₀ melt is 30 % less than the molar volume of an ideal solution of the same composition. The temperature dependence of the melt density is highly nonlinear, therefore the volumetric coefficient of thermal expansion decreases by more than 1.5 times with an increase in temperature from 864 to 1010 K. Based on modern concepts of the structure of liquid metal systems with partially ionic nature of interatomic interaction, the behavior patterns of the volumetric properties of the liquid alloy are briefly analyzed.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"975 - 982"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of flight operating conditions for thermal protection coatings of launch escape propulsion subsystem case","authors":"R. D. Berdov,&nbsp;L. I. Volkova,&nbsp;A. S. Golovatyuk,&nbsp;D. L. Potemkin,&nbsp;V. K. Batygina","doi":"10.1134/S0869864325040122","DOIUrl":"10.1134/S0869864325040122","url":null,"abstract":"<div><p>The paper discusses computational and experimental methods for determining the thermo-erosion characteristics of launch escape propulsion subsystems (LEPS) thermal protection coatings under natural operating conditions. Combustion mixture flow was simulated using a commercial CFD software. Based on the obtained data, heat flux distribution across the LEPS surface was determined. Firing tests conditions of thermal protection materials are also described. A gas-dynamic tunnel (GDT) was used to reproduce the natural operating conditions. Quantitative characteristics of thermo-erosion resistance for materials were calculated based on the experimental results with corrections for the period of transient coating heating.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"945 - 955"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of titaniferous films by the method of magnetron sputtering in a discharge with a small anode followed by annealing in nitrogen and air","authors":"O. V. Zaitsev,&nbsp;T. I. Gareev,&nbsp;O. A. Nerushev,&nbsp;D. V. Sorokin,&nbsp;I. V. Korol’kov,&nbsp;V. S. Sulyaeva","doi":"10.1134/S0869864325040110","DOIUrl":"10.1134/S0869864325040110","url":null,"abstract":"<div><p>The paper describes a method for the synthesis of titanium nitride films using magnetron sputtering in a small-anode discharge. As a result, the synthesized films exhibit the density lower than the density of films produced by the standard method of magnetron sputtering. The generated coatings were subjected to annealing in oxygen-bearing or nitrogen atmosphere. The resulting films were studied using several characteristics and methods: volt-ampere characteristics of the magnetron discharge and the small anode, images from scanning electron microscopy, x-ray phase analysis, resistometry and spectral measurements for optical transparency. Our study demonstrated that the samples synthesized in a setup with an anode are thicker than those synthesized without anode. They also exhibit a smaller size of crystallites, lower transparency, lower band gap and a higher resistance. Taking into account the unaffected regime of magnetron operation, this difference indicates about a lower film density.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"937 - 943"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of swirling flow in a circular pipe after a vane swirler at moderate Reynolds numbers","authors":"V. M. Molochnikov,&nbsp;N. D. Pashkova,&nbsp;A. A. Paereliy","doi":"10.1134/S0869864325040031","DOIUrl":"10.1134/S0869864325040031","url":null,"abstract":"<div><p>The experimental results on the swirling flow structure behind a vane swirler in a smooth pipe at an axial flow Reynolds number varying within Re = 240 – 1640 are presented. A change in the degree of flow swirl along the pipe length is analyzed as a function of the Reynolds number. The main patterns in the evolution of the profiles of longitudinal and circumferential velocity components and the distribution of the root-mean-square fluctuations of the longitudinal velocity component with increasing distance from the swirler are determined. It is shown that at Re = 1640, flow instability develops in the pipe, which is a consequence of the formation of a reverse flow region on the pipe axis in the immediate vicinity of the swirler. The influence of flow swirl on the appearance of signs of a local laminar-turbulent transition in vicinity of the pipe axis and near its wall is analyzed (a sharp increase in the root-mean-square velocity fluctuations with increasing Reynolds number and the appearance of intermittency in the flow velocity oscillograms). It has been established that in the near-wall region, local turbulence of the flow is caused by the interaction between the swirler vane wakes and the wall.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"851 - 866"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the mass flow rate ratio of inlet flows in microchannels on their mixing efficiency: modeling and experiment","authors":"M. V. Kashkarova,&nbsp;Yu. V. Kravtsov,&nbsp;I. V. Naumov,&nbsp;A. Yu. Kravtsova","doi":"10.1134/S0869864325040043","DOIUrl":"10.1134/S0869864325040043","url":null,"abstract":"<div><p>The influence of the mass flow rate ratio of the inlet flows of distilled water on the efficiency of liquid mixing within a T-shaped microchannel was studied using numerical and experimental modeling. The model was verified by comparing the calculated results with experimental data. High-resolution particle image velocimetry was used to measure the flow velocity characteristics. Computer modeling was used to obtain and describe the flow structure and the dynamics of flow pattern changes at unequal mass flow rates. The possibility of increasing the efficiency of liquid mixing by varying the mass flow rate ratio is demonstrated.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"867 - 876"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infrared thermography in studying the laminar-turbulent transition in the boundary layer","authors":"A. V. Boiko,&nbsp;V. I. Borodulin,&nbsp;A. V. Ivanov,&nbsp;S. V. Kirilovsky,&nbsp;D. A. Mischenko,&nbsp;T. V. Poplavskaya,&nbsp;A. D. Cherepanov","doi":"10.1134/S0869864325040055","DOIUrl":"10.1134/S0869864325040055","url":null,"abstract":"<div><p>Methodological issues related to the study of laminar-turbulent transition in subsonic boundary layers using infrared video recording are considered. A method for estimating wall friction based on the analysis of the temperature variation of a preheated model surface is proposed. An improved method for finding the lines of transition onset and completion is proposed.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"877 - 890"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental visualization of a supersonic transversal flow past a circular cylinder with gas jet blowing from the surface holes","authors":"V. A. Kislovskiy,&nbsp;N. A. Ryabchenko,&nbsp;D. A. Semchenko","doi":"10.1134/S0869864325040109","DOIUrl":"10.1134/S0869864325040109","url":null,"abstract":"<div><p>The paper presents results of experimental study on transverse flow past a cylindrical body. Visualization of produced complicated flow pattern is achieved using the shadow method and through particle injection into the flow. Experiments dealt with the case of a classical transversal flow past a cylinder and for a case of gas jet blowing at the cylinder surface. We tested several variants of allocation for injection orifices in circumference within the middle cross section of the cylinder (the cylinder’s aspect ratio <i>λ</i> = 3.2). The research describes the influence of blowing hole position on the flow pattern generated due to supersonic flow-jet interaction.</p><p>The paper presents new experimental results on flow patterns created by supersonic interaction of free-stream and jet for various positions of jet hole; the flow patterns are described and analyzed.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"927 - 935"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear development of unsteady disturbances of a swept-wing boundary layer in the presence of intense crossflow vortices","authors":"V. I. Borodulin,&nbsp;A. V. Ivanov,&nbsp;Y. S. Kachanov,&nbsp;D. A. Mischenko","doi":"10.1134/S086986432504002X","DOIUrl":"10.1134/S086986432504002X","url":null,"abstract":"<div><p>The main goal of the present experimental study is to investigate the mechanism of weakly-nonlinear interaction in a 35-degree swept-wing boundary layer between low-amplitude nonstationary crossflow instability modes and stationary crossflow instability vortices. The crossflow instability dominates in the flow under study while the Tollmien–Schlichting instability is suppressed by a favourable pressure gradient. Stationary disturbances of large amplitude (up to 20 % at the end of the region of measurements) are excited by a surface roughness element. Controlled nonstationary disturbances of small amplitude are generated in the boundary layer by a disturbance source located upstream from the roughness element. Their amplitude in the region of main interaction does not exceed 1%. The source excites quasi-two-dimensional (spanwise-uniform) waves at low frequencies corresponding to the region of primary crossflow instability. The results of hot-wire measurements have shown that the characteristics of the base flow, as well as of the stationary and nonstationary disturbances, do not depend on the amplitude of the latter. Meanwhile, development of the nonstationary disturbances depends very much on the presence of these vortices. Excited quasi-two-dimensional instability waves decay very rapidly downstream, while the forming stationary vortices, growing in a certain spanwise-wavenumber range, transform quasi-two-dimensional waves into strongly three-dimensional ones with a spanwise-wavenumber spectrum corresponding to the most amplifying crossflow instability modes. This transformation does not occur locally in the near field of surface irregularities, but is distributed in the streamwise direction. The growth of stationary disturbance amplitudes is almost exponential. The dependence of their growth rates on the spanwise wavenumber is a characteristic of the crossflow instability modes. Meanwhile, the amplification of the nonstationary disturbances has a complicated and non-monotonous character due to their nonlinear interactions. It is found that in the plane normal to the flow and to the wall, the amplitudes of nonstationary disturbances of all frequencies are strongly localized in the regions with high values of spanwise gradients of the mean flow velocity. An essentially three-dimensional physical mechanism is proposed for the weakly-nonlinear transformation of quasi-two-dimensional waves into three-dimensional ones induced by high-amplitude stationary instability vortices. This mechanism is similar to the “lift-up” effect proposed earlier for explanation of the growth of streaky structures in two-dimensional boundary layers.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"819 - 849"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative investigation of the effects of V-shaped rib configurations on the film cooling performance of laidback fan-shaped holes","authors":"X. Zhang,&nbsp;Y. Pei,&nbsp;H. Luo,&nbsp;K. Ma","doi":"10.1134/S086986432504016X","DOIUrl":"10.1134/S086986432504016X","url":null,"abstract":"<div><p>To evaluate the film cooling performance and underlying flow mechanisms of laidback fan-shaped film holes with an internal cooling channel equipped with distinct V-shaped ribs under the blowing ratios range from 0.5 to 2.0, three rib configurations are considered: smooth channel, continuous V-shaped ribs, and truncated V-shaped ribs. The case with truncated V-shaped ribs performs best on improving film cooling performance at lower blowing ratios, while the case with continuous V-shaped ribs outperforms at higher blowing ratios. The flow mechanism analysis indicates that the rib-induced vortices intensity and distributions, the helical flow intensity inside the film hole and the counter-rotating vortex pair distribution located in the downstream region dominate the film cooling efficiency through different mechanisms. The comparative benefits across various blowing ratios are analyzed according to these key mechanisms.</p></div>","PeriodicalId":800,"journal":{"name":"Thermophysics and Aeromechanics","volume":"32 4","pages":"983 - 1001"},"PeriodicalIF":0.6,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147924247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}