Special Issue "Feature Papers in Section 'Applied Thermal Engineering'"

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Applied Thermal Engineering".

Deadline for manuscript submissions: 31 December 2023 | Viewed by 4437

Special Issue Editors

School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Interests: carbon-neutral energy and power technologies; low-carbon combustion technologies; combustion kinetics and dynamics; novel combustion technologies, such as flame synthesis and plasma-assisted combustion; spray, atomization and evaporation
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
Interests: biomass energy utilization; combustion reaction kinetics; pyrolysis; combustion; gasification; reaction mechanism; catalytic thermal conversion
Special Issues, Collections and Topics in MDPI journals
Space Institute, University of Tennessee, Knoxville, TN 37996, USA
Interests: combustion; reacting flow simulation; multiphysics modeling; engine combustion; alternative fuels; low-carbon fuels; thermodynamics and heat transfer in modern energy devices; Li-ion battery thermal runaway
Special Issues, Collections and Topics in MDPI journals
School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Interests: solar desalination; thermal storage; heat pump

Special Issue Information

Dear Colleagues,

In this Special Issue, entitled “Feature Papers in Section 'Applied Thermal Engineering'”, we invite state-of-the-art research work or comprehensive review papers in the field of Thermal Engineering, and all discussions of technologies related to heat transfer, thermal energy conversion and thermal chemistry processes.

All articles published in this Special Issue are subject to careful editorial selection, but also benefit from high visibility. We aim for this Issue to constitute a forum for disseminating excellent research findings, as well as sharing innovative ideas in the field.

Prof. Dr. Yuyang Li
Prof. Dr. Zhanjun Cheng
Dr. Peng Zhao
Dr. Zhenyuan Xu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2300 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • combustion energy and power
  • low-carbon thermal engineering
  • heat transfer technologies
  • engineering thermodynamics
  • renewable energy
  • building energy conservation
  • zero-emission technologies
  • energy conversion
  • energy storage and heat storage
  • hydrogen and ammonia combustion
  • solar photothermal technology
  • battery thermal management
  • thermal management of electronic devices

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Article
Nozzle Design of Plug-and-Play Passive Pre-Chamber Ignition Systems for Natural Gas Engines
Appl. Sci. 2023, 13(16), 9468; https://doi.org/10.3390/app13169468 - 21 Aug 2023
Viewed by 351
Abstract
To evaluate the significance of the geometrical parameters of a passive pre-chamber on engine performance, this study investigated the design of a plug-and-play passive pre-chamber in a 15 L heavy-duty natural gas engine. Multi-dimensional numerical investigations were conducted for parametric studies involving lateral [...] Read more.
To evaluate the significance of the geometrical parameters of a passive pre-chamber on engine performance, this study investigated the design of a plug-and-play passive pre-chamber in a 15 L heavy-duty natural gas engine. Multi-dimensional numerical investigations were conducted for parametric studies involving lateral angle, orifice diameter, and vertical angle. A compressive flow solver was employed for Navier–Stoke equations, coupled with detailed sub-models and a chemical kinetic scheme. The combustion model was calibrated and could well predict the engine combustion and operating performance. Seven pre-chamber schemes were evaluated, and four optimal ones were selected for experimental tests. The characteristics of the scavenging process, turbulent jet ignition, and main-chamber combustion were investigated and analyzed. The results show that, considering the trade-off between the ignition energy and the scavenging efficiency, the ratio of the pre-chamber to clearance volume is recommended to be 0.2~0.7%, and the corresponding area–volume ratio is 0.003~0.006 mm−1. Compared with the original natural gas engine, the pre-chamber retrofit can save up to 13.2% of fuel consumption, which presents a significant improvement in fuel economy. Full article
(This article belongs to the Special Issue Feature Papers in Section 'Applied Thermal Engineering')
Show Figures

Figure 1

Article
Radiation-Induced Thermal Runaway Propagation in a Cylindrical Li-Ion Battery Pack: Non-Monotonicity, Chemical Kinetics, and Geometric Considerations
Appl. Sci. 2023, 13(14), 8229; https://doi.org/10.3390/app13148229 - 15 Jul 2023
Viewed by 532
Abstract
Li-ion batteries play a key role in energy storage and conversion in engineering systems such as electric vehicles and grid energy storage, with critical impact on electrification and storage of renewable energy. A key unresolved technological challenge in Li-ion batteries pertains to thermal [...] Read more.
Li-ion batteries play a key role in energy storage and conversion in engineering systems such as electric vehicles and grid energy storage, with critical impact on electrification and storage of renewable energy. A key unresolved technological challenge in Li-ion batteries pertains to thermal runaway initiation and propagation in a battery pack, which can lead to subsequent fire and explosion. Despite significant past work, there remains a critical need to understand how thermal runaway propagates in a pack. This work presents a comprehensive investigation of the effect of radiative heat transfer on thermal runaway propagation. Radiation can be important when a battery is exposed to adjacent heat and fire sources, as well as in thermal runaway propagation from one hot cell to another. A theoretical radiative heat transfer model based on view factor theory is developed. Calculations based on this model for a simple 2D cylinder-to-cylinder geometry are found to be in very good agreement with analytical expressions. Radiation-induced thermal runaway propagation between two cylindrical 18650 batteries is evaluated. It is shown that radiation may play a key role in thermal runaway propagation, depending strongly on the triggering temperature. It is found that radiative effects in thermal runaway propagation exhibit both nonlinear and non-monotonic characteristics. At high temperatures, thermal runaway is triggered rapidly in the region close to the battery surface, where the chemical reactions are strongly coupled, and radiation plays a dominant role. In contrast, at lower temperatures, thermal runaway is triggered much more slowly and towards the core of the cell, where some chemical reactions may be decoupled, and pre-runaway chemical heat release plays an increasingly important role. The results presented here suggest that radiation can either facilitate or mitigate thermal runaway. The net radiation heat flux has a cross-over instant, beyond which radiation starts to retard thermal runaway. Additionally, the blocking effect in radiative heat transfer between cells arranged in equal-spacing homogenous or orthogonal arrangements in a battery pack is investigated, along with the effect of the hot spot size. Results from this work help understand the role of radiation in thermal runaway propagation and provide useful insights into the thermal runaway control and design of safe Li-ion battery packs. Full article
(This article belongs to the Special Issue Feature Papers in Section 'Applied Thermal Engineering')
Show Figures

Figure 1

Article
Modeling and Performance Analysis of a Pump-Driven Chip-Level Two-Phase Cooling System in Data Centers
Appl. Sci. 2023, 13(13), 7472; https://doi.org/10.3390/app13137472 - 24 Jun 2023
Viewed by 785
Abstract
As a powerful solution for heat dissipation in data centers, chip-level cooling continues to capture escalating attention in research and application domains. To accurately analyze system performance, identify potential avenues for system optimization, and inform future practical applications, we developed a steady-state, one-dimensional [...] Read more.
As a powerful solution for heat dissipation in data centers, chip-level cooling continues to capture escalating attention in research and application domains. To accurately analyze system performance, identify potential avenues for system optimization, and inform future practical applications, we developed a steady-state, one-dimensional mathematical model for a novel pump-driven chip-level two-phase cooling system (PCTCS). This model was constructed based on our previous study and was confirmed against existing experimental data. Our simulations scrutinized PCTCS performance under default conditions and investigated the effects of key parameters, such as refrigerant type, condenser vertical positioning, and cooling water temperature. Results showed that the system could manage an 80 W power output from each CPU while maintaining CPU temperatures around 79 °C at a cooling water temperature of 45 °C. We discovered the choice of refrigerant had a significant impact on performance, with R32 outperforming R134a and R113. While the vertical position of the condenser influenced the PCTCS’s internal parameters, its overall impact on system performance was negligible. Moreover, provided the chip temperature remained within a safe range, our study found that increasing the cooling water temperature improved the energy efficiency ratio of the refrigerant pump and reduced the temperature difference between the chips and the cold source. Full article
(This article belongs to the Special Issue Feature Papers in Section 'Applied Thermal Engineering')
Show Figures

Figure 1

Article
Characterization of Nonlinear Responses of Non-Premixed Flames to Low-Frequency Acoustic Excitations
Appl. Sci. 2023, 13(10), 6237; https://doi.org/10.3390/app13106237 - 19 May 2023
Viewed by 542
Abstract
The response of flames’ heat release to acoustic excitation is a critical factor for understanding combustion instability. In the present work, the nonlinear heat release response of a methane–air non-premixed flame to low-frequency acoustic excitations is experimentally investigated. The flame describing function (FDF) [...] Read more.
The response of flames’ heat release to acoustic excitation is a critical factor for understanding combustion instability. In the present work, the nonlinear heat release response of a methane–air non-premixed flame to low-frequency acoustic excitations is experimentally investigated. The flame describing function (FDF) was measured based on the overall CH* chemiluminescence intensity and the velocity fluctuations obtained by the two-microphone method. The CH* chemiluminescence and schlieren images were analyzed for revealing the mechanism of nonlinear response. The excitation frequency ranges from 10 Hz to 120 Hz. The forced relative velocity fluctuation amplitude ranges from 0.10 to 0.50. The corresponding flame Strouhal number (Stf) ranges from 0.43 to 4.67. The study has shown that the flame length responds more sensitively to changes in excitation amplitude when subjected to relatively high-frequency excitations. The normalized flame length (Lf/D) decreases from 3.79 to 2.37 with the increase in excitation amplitude at an excitation frequency of 100 Hz. The number of oscillation zones along the flame increases with increasing excitation frequency, which is consistent with the increase in the Stf. The low-pass filtering characteristic of FDF is caused by the dispersion of multiple oscillation zones, as well as the cancellation effect of the adjacent oscillation zones under relatively high-frequency excitation. The main mechanism for the local gain peak and valley is the cancellation effect of positive and negative oscillation zones with various Stf. When two adjacent oscillation regions have similar amplitudes, the overall phase-lag becomes more sensitive to changes in excitation frequency and amplitude. This sensitivity leads to nonlinear anomalous changes in the phase-lag near the frequency corresponding to the gain valley. The calculated disturbance convection time is consistent with the measured time delay in the short flame scenario. Further research is required to determine whether the identified agreement is a result of the consistent occurrence of the oscillation zone in close proximity to the flame’s center of mass, in conjunction with a precise determination of the average convective velocity. Full article
(This article belongs to the Special Issue Feature Papers in Section 'Applied Thermal Engineering')
Show Figures

Figure 1

Article
Characterizing Internal Flow Field in Binary Solution Droplet Combustion with Micro-Particle Image Velocimetry
Appl. Sci. 2023, 13(9), 5752; https://doi.org/10.3390/app13095752 - 06 May 2023
Viewed by 651
Abstract
Droplet internal flow participates in liquid-phase mass transfer during multicomponent solution droplet combustion. In this work, internal flow fields in the binary droplet combustion of two polyoxymethylene dimethyl ethers (CH3O(CH2O)nCH3, n ≥ 1, abbreviated as [...] Read more.
Droplet internal flow participates in liquid-phase mass transfer during multicomponent solution droplet combustion. In this work, internal flow fields in the binary droplet combustion of two polyoxymethylene dimethyl ethers (CH3O(CH2O)nCH3, n ≥ 1, abbreviated as PODEn), i.e., PODE2 and PODE4, are characterized using micro-particle image velocimetry (Micro-PIV). The buoyancy-driven upward vapor flow around the droplet is found to initiate two opposite radial flows in the droplet, which form two vortex cores near the surface, while the gravitational effect and Marangoni effect resulting from the content and temperature gradients in the binary droplets can induce disturbance to the two flows. The binary droplets have comparable spatially averaged flow velocities at the stable evaporation stage to those of pure droplets, which are around 3 mm/s. The velocity curves are more fluctuant and tend to slightly increase and reach the peak values at around 250 ms, and then decrease until droplet atomization. The flow velocities in the droplet interior are generally higher than those near the droplet surface, forming a parabolic velocity profile along the horizontal radial direction. The peak velocity first increases to 5–9 mm/s as the radial flow and vortex structure start to form and then decreases to around 3 mm/s until droplet atomization. The radial flow with a spatially averaged velocity of 3 mm/s can run around one lap during the stable evaporation stage, which implies that the convection-induced mass transfer is relatively weak, and consequently, the content gradient of the binary droplet is still mainly controlled by mass diffusion. Full article
(This article belongs to the Special Issue Feature Papers in Section 'Applied Thermal Engineering')
Show Figures

Figure 1

Article
Modeling and Analysis of Contactless Solar Evaporation for Scalable Application
Appl. Sci. 2023, 13(6), 4052; https://doi.org/10.3390/app13064052 - 22 Mar 2023
Viewed by 938
Abstract
Zero-liquid discharge wastewater treatment driven by sunlight shows potential to minimize its environmental impact by producing solid-only waste from solar energy. To overcome the key barrier of solar absorber contamination, solar-driven contactless evaporation (SCE) has been proposed. However, only a small-scale laboratory device [...] Read more.
Zero-liquid discharge wastewater treatment driven by sunlight shows potential to minimize its environmental impact by producing solid-only waste from solar energy. To overcome the key barrier of solar absorber contamination, solar-driven contactless evaporation (SCE) has been proposed. However, only a small-scale laboratory device has been studied, which cannot support its scalable application. To analyze the potential of SCE, it is essential to understand the conjugated heat and mass transfer under a scalable application scenario. In this study, a comprehensive model of SCE is developed, which is validated by the laboratory evaporation test and applied to scalable evaporation scenario. Results showed that the scalable evaporation (0.313 kg·m−2·h−1) could obtain higher evaporation rate than the laboratory evaporation (0.139 kg·m−2·h−1) due to suppressed heat losses from the sidewalls. If the design parameters are finely tuned and thermal insulation are properly applied, the evaporation rate could be further enhanced to 0.797 kg·m−2·h−1, indicating a 473.3% performance enhancement than the laboratory SCE. The modelling framework and understanding are expected to pave a way for the further improvement and scalable application of SCE. Full article
(This article belongs to the Special Issue Feature Papers in Section 'Applied Thermal Engineering')
Show Figures

Figure 1

Back to TopTop