@article{51122, author = {{Al-Lami, Abbas J.S. and Kenig, Eugeny Y.}}, issn = {{2214-157X}}, journal = {{Case Studies in Thermal Engineering}}, keywords = {{Fluid Flow and Transfer Processes, Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{New pressure drop and heat transfer correlations for turbulent forced convection in internally channeled tube heat exchanger ducts}}}, doi = {{10.1016/j.csite.2024.103993}}, year = {{2024}}, } @article{43457, abstract = {{The production of hydrogen and the utilization of biomass for sustainable concepts of energy conversion and storage require gas sensors that discriminate between hydrogen (H2) and carbon monoxide (CO). Mesoporous copper–ceria (Cu–CeO2) materials with large specific surface areas and uniform porosity are prepared by nanocasting, and their textural properties are characterized by N2 physisorption, powder XRD, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The oxidation states of copper (Cu+, Cu2+) and cerium (Ce3+, Ce4+) are investigated by XPS. The materials are used as resistive gas sensors for H2 and CO. The sensors show a stronger response to CO than to H2 and low cross-sensitivity to humidity. Copper turns out to be a necessary component; copper-free ceria materials prepared by the same method show only poor sensing performance. By measuring both gases (CO and H2) simultaneously, it is shown that this behavior can be utilized for selective sensing of CO in the presence of H2.}}, author = {{Baier, Dominik and Priamushko, Tatiana and Weinberger, Christian and Kleitz, Freddy and Tiemann, Michael}}, issn = {{2379-3694}}, journal = {{ACS Sensors}}, keywords = {{Fluid Flow and Transfer Processes, Process Chemistry and Technology, Instrumentation, Bioengineering}}, number = {{4}}, pages = {{1616 -- 1623}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Selective Discrimination between CO and H2 with Copper–Ceria-Resistive Gas Sensors}}}, doi = {{10.1021/acssensors.2c02739}}, volume = {{8}}, year = {{2023}}, } @article{34223, abstract = {{In this study, quasi-unidirectional continuous fiber reinforced thermoplastics (CFRTs) are joined with metal sheets via cold formed cylindrical, elliptical and polygonal pin structures which are directly pressed into the CFRT component after local infrared heating. In comparison to already available studies, the unique novelty is the use of non-rotational symmetric pin structures for the CFRT/metal hybrid joining. Thus, a variation in the fiber orientation in the CFRT component as well as a variation in the non-rotational symmetric pins’ orientation in relation to the sample orientation is conducted. The created samples are consequently mechanically tested via single lap shear experiments in a quasi-static state. Finally, the failure behavior of the single lap shear samples is investigated with the help of microscopic images and detailed photographs. In the single lap shear tests, it could be shown that non-rotational symmetric pin structures lead to an increase in maximum testing forces of up to 74% when compared to cylindrical pins. However, when normalized to the pin foot print related joint strength, only one polygonal pin variation showed increased joint strength in comparison to cylindrical pin structures. The investigation of the failure behavior showed two distinct failure modes. The first failure mode was failure of the CFRT component due to an exceedance of the maximum bearing strength of the pin-hole leading to significant damage in the CFRT component. The second failure mode was pin-deflection due to the applied testing load and a subsequent pin extraction from the CFRT component resulting in significantly less visible damage in the CFRT component. Generally, CFRT failure is more likely with a fiber orientation of 0° in relation to the load direction while pin extraction typically occurs with a fiber orientation of 90°. It is assumed that for future investigations, pin structures with an undercutting shape that creates an interlocking joint could counteract the tendency for pin-extraction and consequently lead to increased maximum joint strengths.}}, author = {{Popp, Julian and Römisch, David and Merklein, Marion and Drummer, Dietmar}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}}, number = {{10}}, publisher = {{MDPI AG}}, title = {{{Joining of CFRT/Steel Hybrid Parts via Direct Pressing of Cold Formed Non-Rotational Symmetric Pin Structures}}}, doi = {{10.3390/app12104962}}, volume = {{12}}, year = {{2022}}, } @article{34224, abstract = {{Crack growth in structures depends on the cyclic loads applied on it, such as mechanical, thermal and contact, as well as residual stresses, etc. To provide an accurate simulation of crack growth in structures, it is of high importance to integrate all kinds of loading situations in the simulations. Adapcrack3D is a simulation program that can accurately predict the propagation of cracks in real structures. However, until now, this three-dimensional program has only considered mechanical loads and static thermal loads. Therefore, the features of Adapcrack3D have been extended by including contact loading in crack growth simulations. The numerical simulation of crack propagation with Adapcrack3D is generally carried out using FE models of structures provided by the user. For simulating models with contact loading situations, Adapcrack3D has been updated to work with FE models containing multiple parts and necessary features such as coupling and surface interactions. Because Adapcrack3D uses the submodel technique for fracture mechanical evaluations, the architecture of the submodel is also modified to simulate models with contact definitions between the crack surfaces. This paper discusses the newly implemented attribute of the program with the help of illustrative examples. The results confirm that the contact simulation in Adapcrack3D is a major step in improving the functionality of the program.}}, author = {{Joy, Tintu David and Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}}, number = {{15}}, publisher = {{MDPI AG}}, title = {{{Further Development of 3D Crack Growth Simulation Program to Include Contact Loading Situations}}}, doi = {{10.3390/app12157557}}, volume = {{12}}, year = {{2022}}, } @article{44041, author = {{Ahmadov, A. I. and Nagiyev, Sh. M. and Aydin, C. and Tarverdiyeva, V. A. and Orujova, M. Sh. and Badalov, S. V.}}, issn = {{2190-5444}}, journal = {{The European Physical Journal Plus}}, keywords = {{General Physics and Astronomy, Fluid Flow and Transfer Processes}}, number = {{9}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Bound state solutions of Dirac equation: spin and pseudo-spin symmetry in the presence of the combined Manning–Rosen and Yukawa tensor potentials}}}, doi = {{10.1140/epjp/s13360-022-03255-9}}, volume = {{137}}, year = {{2022}}, } @article{30213, abstract = {{Requirement changes and cascading effects of change propagation are major sources of inefficiencies in product development and increase the risk of project failure. Proactive change management of requirement changes yields the potential to handle such changes efficiently. A systematic approach is required for proactive change management to assess and reduce the risk of a requirement change with appropriate effort in industrial application. Within the paper at hand, a novel method for Proactive Management of Requirement Changes (ProMaRC) is presented. It is developed in close collaboration with industry experts and evaluated based on workshops, pilot users’ feedback, three industrial case studies from the automotive industry and five development projects from research. To limit the application effort, an automated approach for dependency analysis based on the machine learning technique BERT and semi-automated assessment of change likelihood and impact using a modified PageRank algorithm is developed. Applying the method, the risks of requirement changes are assessed systematically and reduced by means of proactive change measures. Evaluation shows high performance of dependency analysis and confirms the applicability and usefulness of the method. This contribution opens up the research space of proactive risk management for requirement changes which is currently almost unexploited. It enables more efficient product development.}}, author = {{Gräßler, Iris and Oleff, Christian and Preuß, Daniel}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}}, number = {{4}}, publisher = {{MDPI AG}}, title = {{{Proactive Management of Requirement Changes in the Development of Complex Technical Systems}}}, doi = {{10.3390/app12041874}}, volume = {{12}}, year = {{2022}}, } @article{35327, author = {{Wortmann, Martin and Viertel, Klaus and Welle, Alexander and Keil, Waldemar and Frese, Natalie and Hachmann, Wiebke and Krieger, Philipp and Brikmann, Johannes and Schmidt, Claudia and Moritzer, Elmar and Hüsgen, Bruno}}, issn = {{0017-9310}}, journal = {{International Journal of Heat and Mass Transfer}}, keywords = {{Fluid Flow and Transfer Processes, Mechanical Engineering, Condensed Matter Physics}}, publisher = {{Elsevier BV}}, title = {{{Anomalous bulk diffusion of methylene diphenyl diisocyanate in silicone elastomer}}}, doi = {{10.1016/j.ijheatmasstransfer.2021.121536}}, volume = {{177}}, year = {{2021}}, }