Thermal Jacket Research Articles

Experimental and Numerical Study on the Protection Efficiency of a Diamond-Shaped Thermal Jacket for Gun Barrels

Abstract Experimental and numerical investigations on the protection efficiency of a diamond-shaped thermal jacket made of the certain braided composites with anisotropic material properties for gun barrels were carried out to gain an insight into its thermal–structural behavior and performance. The experiments for the gun barrels with and without the thermal jacket subjected to unilateral thermal radiation were conducted on a thermal jacket protection efficiency experimental system. Three-dimensional finite element models were established to perform the thermal–structural analysis and approximate the temperature distribution and thermal deformation of the shrouded gun barrel and bare gun tube. The experimental results validated the numerical models for the study of solar radiation on the thermal–structural characteristics of the gun barrels with and without the thermal jacket. The temperature changes together with their gradients, and the thermal deformation of the gun tube shrouded with the thermal jacket were notably less than that of the bare gun tube. The nonuniform temperature distribution caused by unilateral radiation can be substantially ameliorated by the thermal jacket. The developed diamond-shaped thermal jacket owned satisfactory protection effectiveness. In addition, moderately increasing the thermal jacket's thickness or the air gap between the thermal jacket and gun tube can decrease the muzzle deflection of the shrouded gun barrels. The work is promising in providing both theoretical and practical contributions in design of shrouded tank gun barrels aiming at achieving high first shot accuracy.

RCS Computation and Analysis of a Diamond-shaped Thermal Jacket for Gun Barrels

A research on RCS simulations and analysis of a diamond-shaped thermal jacket was carried out, to make thermal jackets on tanks less detectable to known radar observation methods. Based on the principles of radar stealth technology, a diamond-shaped thermal jacket was modeled. The RCS simulation models were established by employing the physical optics method (PO), the monostatic RCS characteristics of the diamond-shaped thermal jacket at high frequency region was investigated, and the major components affecting the radar scattering characteristics were evaluated. The original end part played a major role in the radar scattering characteristics of the diamond-shaped thermal jacket. The RCS simulation of thermal jackets in various shapes, including the cylinder-shaped, the original diamond-shaped, and the diamond-shaped without the original end part are carried out, and a comparative evaluation of the schemes is provided. The results show that trans-shaping the cylinder-shaped model to the diamond-shaped model is a method to effectively reduce the average RCS of the thermal jackets in the frontal and lateral directions, improve the overall stealth performance of tank guns. The work is beneficial for design and evaluation concerning about the shape stealth technology of thermal jackets for gun barrels.

Simulation Study of Structural Factors Affecting the Performance of Thermal Jacket for Gun Tubes

Most of common thermal jackets for gun tubes are composite types, which have large mass and complex structures. With the development of material technology, a single-layer thermal jacket using new composite materials with low thermal conductivity has good protection effects on gun tubes. The design of a single-layer thermal jacket requires consideration of thickness, air gap, material properties and structural strength. In order to study the structural factors that affect the performance of the single-layer heat jacket, the models of various structural dimensions through a 3D modeling software were established, a thermal-mechanical coupling system was built using a finite element simulation software to simulate the different thermal jacket models. The results were compared and analyzed, and the structural factors that affect the performance of the thermal jacket were investigated.

Avail of the glass wool properties using the aperture-coupled technique to design a thermal smart jacket

Avail of the glass wool properties using the aperture-coupled technique to design a thermal smart jacket

Автоматизация теплового расчета реактора для производства серосодержащего сорбента при разогреве реакционной смеси

The article highlights the problem of automation the thermal design of a reactor for the synthesis of a sulfur-containing sorbent obtained from the use of waste products of epichlorohydrin, chlorinated lignin and sodium polysulfides is considered. Automated design helps to reduce the intensity of the process, improve the quality of design decisions, significantly reduce production costs, which has a positive effect on the cost of finished products. It has been found that due to the incompatibility of the similarity criteria of chemical and mass transfer processes there is little possibility to carry out a large-scale transition in a reactor based on physical similarity. In the course of a large-scale transition from a laboratory unit to a small production unit there were used the computational methods based on engineering experience that allow increasing the reliability of the results obtained. There have been determined the initial values, which will be used in the design for a reactor with a propeller agitator to mix a working mass having a dynamic viscosity coefficient of 6.01 sP and a solid phase content of 31.8%. The agitator type was determined by calculating the physical properties of the ingredients and selecting the mixer designs. A flowchart and a formal description of the algorithm for calculating heat transfer during a reaction mixture heating are given; the program interface is written in C# displaying the results of thermal design of the working mixture heating. As a result of the calculation, there has been calculated the amount of heat and time required to heat the working mixture, coefficient of heat transfer from the working mass to the reactor wall, mass flow rate of water and its costs, velocity of water in the thermal jacket, mode of water flow in the jacket and other similarity criteria.

The effect of post-brew holding time and carafe type on the sensory properties of drip brew coffee.

Coffee quality is believed to degrade quickly after brewing, and retail establishments discard unsold brewed coffee after a specified holding time period, sometimes as short as 30 min. We used trained sensory panels to evaluate the flavor profiles of light, medium, and dark roast coffees held in three different carafe types (glass on hot plate, thermal jacket, and vacuum insulated) for times ranging from 15 min to 3h. Furthermore, a panel of 93 coffee-industry professionals performed a blind evaluation of fresh (30 min) versus held (180 min) coffee for overall liking and attribute level adequacy. Sourness increased over time, consistent with acidity increasing over time (i.e., higher titratable acidity, lower pH), but only for the light and medium roasts. Dark roasted coffee became significantly more acidic over 3 h post-brew but was not perceived as more sour over time by the sensory panel. Variations were observed between the thermal jacket and vacuum carafes for the light and dark roast, but few differences were observed with storage type in the medium roast. Surprisingly, the panel of coffee industry professionals showed no preference for fresh over held. More sensory attributes decreased than increased over time, suggesting that the primary concern with loss of quality during coffee holding may be the loss of volatile aroma compounds. Hedonic ratings suggest that even if the changes over time are noticeable, they may not negatively impact overall liking. © 2022 Society of Chemical Industry.

Comparative physiological and hygienic assessment of the personal protective equipment EP-4(0) in the various assembly according to human thermal state indices

Introduction. The article presents results of the study of the impact of the personal protective equipment EP-4 (0) in various assembly (overalls, jacket and trousers, jacket and semi-overall) from power frequency electric field and electrical shock on the thermal state of workers in a heating environment at air temperature 34.8 ○C and relative humidity 48%. Materials and methods. The study involved three men aged 35.3±4.6 years. They did the physical exercise for 40 minutes, had comfortable relaxation for 30 minutes after work. Recorded indices included skin temperature and moisture sensation score on 11 parts of the body, body temperature in the ear canal, heart rate, clothes temperature, heat sensation score, moisture loss, moisture evaporation efficiency. Results. Overalls using had the highest values of heat content, moisture score, heart rate changes, and body temperature increment. Heat content index in the body reached maximum permissible value using overalls earlier than other configurations. Conclusion. The research data showed overalls have the most significant impact on the human thermal state, jacket and trousers have the least impact, jacket and semi-overall take an intermediate place. The configuration including jacket and trousers, jacket and semi-overall under specific operating conditions is the most optimal. Such PPE assembly can be recommended for use in the open area in the summer season at an air temperature of 35 ○C and above, subject to protective requirements.

Energy analysis of a micro-scale biomass cogeneration system

Microscale heating devices are mandatory for users located in areas lacking of heating networks, especially in the rural ones. An interesting option for schools, farms, houses, and other users is to increase the functionality of heating devices with the power generation option. Such systems may operate on the basis of a simple Rankine Cycle fired by biomass. In this paper, the energy and economic parameters of a prototype micro-cogeneration system based on a 100 kWth straw-fired boiler with a thermal oil jacket and a 14.8 kW steam engine were investigated. During the experimental tests, the power at a level of 1.1 kWel was obtained by the prototype installation when steam pressure was equal to 4.3 bars and steam mass flow was about 105 kg/h. The relatively low electric power resulted from a limited heat exchange surface of the evaporator and, undersized nominal power of electricity generator and piping heat and pressure losses. On the other hand, the maximum measured pressure was 10 bars, when steam temperature was ca. 200 °C, pointing out that the installation has a significant potential of improvement from the power generation point of view. A dynamic simulation model was developed using TRNSYS software in order to investigate the system capabilities. This model was calibrated using experimental investigations, and further technical improvements of the installation were analyzed from energy and economic points of view. The possibility of integrating an absorption chiller in the system was also considered. As a result, the operation of the existing micro-cogeneration system was simulated and the operation parameters of the proposed micro trigeneration system were analyzed.

Protection From the Second Warm Ischemic Injury in Kidney Transplantation Using an Ex Vivo Porcine Model and Thermally Insulating Jackets

BackgroundKidney transplantation is the optimum treatment for kidney failure in carefully selected patients. Technical surgical complications and second warm ischemic time (SWIT) increase the risk of delayed graft function (DGF) and subsequent short- and long-term graft outcomes including the need for post-transplant dialysis and graft failure. Intraoperative organ thermal regulation could reduce SWIT, minimizing surgical complications due to time pressure, and limiting graft ischemia-reperfusion injury. MethodsA novel ischemic-injury thermal protection jacket (iiPJ) was designed and fabricated in silicone composite and polyurethane (PU) elastomer prototypes. Both were compared with no thermal insulation as controls. Time to reach ischemic threshold (15°C) and thermal energy transfer were compared. A water bath model was used to examine the thermal protective properties of porcine kidneys, as a feasibility study prior to in vivo translation. ResultsIn both iterations of the iiPJ, the time taken to reach the warm ischemia threshold was 35.2 ± 1.4 minutes (silicone) and 38.4 ± 3.1 minutes (PU), compared with 17.2 ± 1.5 minutes for controls (n = 5, P < .001 for both comparisons). Thermal energy transfer was also found to be significantly less for both iiPJ variants compared with controls. There was no significant difference between the thermal performance of the 2 iiPJ variants. ConclusionProtection from SWIT by using a protective insulation jacket is feasible. With clinical translation, this novel strategy could facilitate more optimal surgical performance and reduce transplanted organ ischemia-reperfusion injury, in particular the SWIT, potentially affecting delayed graft function and long-term outcomes.

Effects of nanocomposite polymer flooding on Egyptian crude oil recovery

In this work, a laboratory study of enhanced oil recovery (EOR) was carried out using Egyptian crude oil of 37°API extracted from a reservoir in the Western Desert to identify the optimum conditions for the application of locally prepared nanocomposite polymer flooding under harsh reservoir condition. In contrary to the other studies, we tested the ability of nanocomposite polymer where nanoparticles are involved in the polymer matrix during polymerization process. Measurements of viscosity and shear rate of several solutions were taken. Displacement runs were conducted at different conditions of nanocomposite polymer salinities (10,000, 20,000, 30,000, 40,000, 50,000, 60,000 and 65,000 ppm), concentrations (1, 1.5, 2, 2.5, 3, 3.5 and 4 g/L) and slug sizes (0.2, 0.4, 0.6 and 0.8 PV). A linear sandpack (length of 62.5 cm and diameter of 2″) was prepared and wrapped with thermal jacket to simulate several reservoir temperatures. It was filled by selected sand size to produce linear sandpack model with reasonable porosity (22%) and permeability (129–157 mD) values. The model was used to perform several displacements runs for waterflooding and nanocomposite polymer flooding. The results of the flood runs are analyzed using the water–oil relative permeability curves. The measurements of the solutions properties showed that the critical concentration of the used nanocomposite polymer in the solution is 2 g/L. Also, it was observed that the used nanocomposite polymer solution could withstand a salinity of 60,000 ppm. As a result of the flooding, it was found that the optimum economical slug size of the used nanocomposite polymer is 0.4 PV at reservoir temperature of 40 °C. The results indicated also that the used nanocomposite polymer could withstand a reservoir temperature of 90 °C. The water–oil relative permeability curves showed an enhancement of oil relative permeability and a decrease in the water relative permeability using nanocomposite polymer over waterflooding. The cost of the used nanocomposite polymer with a concentration of 2 g/L and slug size of 0.4 PV is 0.626 $ for each barrel of the incremental oil recovery. Based on the results of this work, it is clear that involving nanoparticles such as silica in the polymer matrix composition improves its properties, thermal and salinity resistivity. Such study is an original contribution to carry out successful nanocomposite polymer EOR projects.

Comparative Analysis of the Thermal Insulation of Multi-Layer Thermal Inserts in a Protective Jacket.

This paper presents the measurement results of the thermal insulation of the outer shell, thermal inserts, and clothing systems, as well as a comparative analysis of the thermal insulation of multi-layer thermal inserts in a thermal jacket intended for professional services in cold weather. Detachable thermal inserts are made of double-faced, diamond-shaped quilted lining with different masses per unit area, and together with the jacket, they form clothing systems with different thermal properties. Tests of the thermal properties of clothing were performed on a thermal manikin. They showed that an increase in the mass of thermal insulation textile materials contributes to an increase in the thermal insulation properties of clothing and are insufficient for a complete analysis of the thermal properties of clothing. Therefore, for the first time, three new parameters of integration efficiency of the thermal insert, thermal insulation efficiency parameters, and efficiency parameters of the integration of the textile material integrated into the clothing system were introduced. Based on these parameters, it is possible to perform an effective and accurate comparative analysis of the thermal insulation of multi-layer thermal inserts in clothing. This makes it possible to apply exact scientific methods largely in the technical design of the thermal properties of integrated textile materials, instead of experience-based methods as in the past.

A parametric study of the drying process of polypropylene particles in a pilot-scale fluidized bed dryer using Computational Fluid Dynamics

Fluidized Bed Dryer (FBD) is one of the efficient methods for drying moist particulate products. At the same time, the design and optimization of a full industrial scale FDB requires extensive studies. Using a pilot-scale dryer can be deemed as an efficient tool to obtain essential information on the drying phenomenon. Although these kinds of experimental analyses can provide valuable insight, there are still some operational limitations, including high-pressure or high-temperature conditions, which make the use of a computational procedure highly desirable. In this study, Computational Fluid Dynamics (CFD) approach has been employed to investigate a dryer. The results of numerical simulations were verified using the experimental data obtained from a pilot-scale dryer. The present investigation aims to study the effects of different operating conditions. It was observed that the impacts of gas inlet temperature were negligible, as the dryer was equipped with a thermal jacket, while the gas injection velocity had significant effects on the dryer’s performance. Moreover, the efficiencies of the conical and horizontal gas distributors were compared and it was concluded that the conical configuration results in better performance. The numerical and experimental investigation from this study can facilitate the design and scale-up of an industrial dryer plant.

Advances in the development of latent heat storage materials based on inorganic lithium salts

Recently, inorganic thermal energy (TES) storage materials to support renewable energy implementation are being developed, and lithium salts have been showing thermal properties suitable for latent storage applications. There are three main technologies to achieve TES: sensible, latent, and thermochemical energy storage. Latent heat storage materials or phase change materials (PCMs) can store large amounts of heat per volume and they can be applied at a certain temperature, depending on the desired application. Lithium compounds for sensible storage have been reviewed in previous publications. Their use in latent heat storage applications is increasing but scarcely documented; while new latent heat storage Li materials appear consistently, the information on them is still dispersed. Therefore, the main objective of this study is to discuss lithium compounds used, proposed or analyzed for latent heat storage (LHS) and their possible applications. Lithium salts thermophysical properties, such as density, melting temperature and latent heat were tabulated as found in literature. Binary salts presented attractive heat of fusion values over 130 kJ kg−1 in a wide range of temperatures. Moreover, the increase of stability of multi-component PCM systems due to the insertion of lithium compounds was confirmed. The technologies to produce lithium are improving and, if the demand increases, prices could decrease in the near future. Therefore, the availability of lithium materials was also analyzed in this study. Finally, potential applications of these thermal storage materials, such as heated underwater diver suits, portable thermal conditioning jackets, solar receiver space, Stirling engines, etc. were assessed.

Heat and sound insulation applications of pineapple aerogels from pineapple waste

Given the harmful effects of agricultural waste residues on the environment and the abundance of pineapple byproducts after harvest, converting pineapple waste into a high-engineering value product for practical applications is one of the solutions toward sustainable development in developing countries. For the first time, flexible cellulose aerogels from raw pineapple-leave fibers (PALF) are developed successfully by using an adhesive agent, polyvinyl alcohol (PVA), and deionized (DI) water as a solvent, followed by a freeze-drying process. The effects of the pineapple fiber (PF) concentration on the heat and acoustic insulation properties are also investigated. The PF aerogels show high porosities of nearly 99%, ultra-low densities of (0.013–0.033) g/cm3, and a microporous structure which are determined by FE-SEM, BET and XRD analysis. They have very low thermal conductivities of (0.030–0.034) W/mK, indicating their excellent suitability for heat insulation applications. Indeed, the thermal jacket using a PF aerogel as filler wrapped around a water bottle can maintain the water temperature below 0 °C for 6 h (initial temperature of −3 °C), and above 40 °C for 2.5 h (initial temperature of 90 °C). The heat insulation capacity of the thermal jacket is about three times better than that of a commercially available product. With the same thickness, the noise reduction coefficient of 2.0 wt% PF aerogel samples is greater than that of a commercial absorber Basmel, which demonstrates their potential in acoustic insulation applications.

Development of Intelligent Models for the Prediction the Dynamics of Nonlinear Process

The use of artificial intelligence (AI) techniques to address nonlinearity problems is gaining importance, mainly in context of industry 4.0. The present work was development of models based on artificial intelligence was performed to predict the concentration of cyclopentenol in a CSTR chemical reactor with the Van De Vusse kinetics. This reaction is known for its nonlinear behavior, which makes prediction difficult. Using simulations of this reactor in open and closed mesh combined with certain perturbations, a database was generated to train the models. The software MATLAB 2018a was used to implement the neural and the ANFIS systems. The input layer could be feed flow, feed temperature, heat provided by the thermal jacket, outlet temperature. The output were concentration of the component B and reactor temperature one step ahead. The models had good agreement, once presented remarkable performance reproducing the dynamics, obtaining R² values near to 1 and error index near to 0.

Mixed Vapor Generation Device for delivery of homemade explosives vapor plumes

While there is a large body of research on the properties and detection of traditional military high explosives and propellant low explosives, there is a dearth of research on homemade explosive (HME) materials, though they are prevalent today. The safety of working with these materials in the laboratory is the greatest limiting factor preventing HME research. A vapor delivery tool, the Mixed Vapor Generation Device (MV-Gen), was designed to safely contain the individual solid or liquid components that often compose homemade explosives vapor plumes and deliver the mixed component vapors for instrumental sampling and analysis. Within the MV-Gen, each component is separated and only the vapors mix as they are carried through the device by flowing air. The resulting mixed vapor is representative of either mixed explosive material or bulk explosives. Component materials are held in up to four individual, removable vials with vapor concentrations controlled by vial orifice size, temperature, and diluent airflow. The total concentration can be adjusted by altering vial temperature via a thermal water jacket surrounding the entirety of the device, or by adjusting the flow rate of diluent air through the device. The MV-Gen was evaluated first with surrogate compounds, followed by two types of homemade explosives, to include a binary explosive mixture and a peroxide explosive. To evaluate the device, vapors were cold-trapped on an online sampling system and analyzed by gas chromatography/mass spectrometry. It was determined that the device yielded reproducible vapor concentrations of both single and mixed components, and the ratio of these vapors can be easily adjusted to mimic varying forms of homemade explosives.

Modeling and Numerical Simulation of Hydrogen Production from Dimethyl Ether Steam Reforming

In order to study the steam reforming process of dimethyl ether, a kind of reformer reactor with thermal jacket, heat pipe and catalytic reaction bed was designed. The effects of reaction gas temperature, molar ratio of water to ether and the structure parameters of the reactor on the conversion of dimethyl ether, the yield of hydrogen, the hydrogen concentration at the outlet of the reactor and the concentration of CO2 were investigated experimentally. The mathematics and power of the reactor were established Learn model The COMSOL software was used to simulate it. The simulation results showed the temperature distribution, mass distribution, DME conversion and hydrogen production in DME steam reforming process. These simulation results will provide useful data for the design and operation of small scale catalytic reforming bed reactors.

Thermal Jacket Design Using Cellulose Aerogels for Heat Insulation Application of Water Bottles

Thermal jacket design using eco-friendly cellulose fibers from recycled paper waste is developed in this report. Neoprene as an outmost layer, cellulose aerogels in the middle and Nylon as an innermost layer can form the best sandwiched laminate using the zigzag stitching method for thermal jacket development. The temperature of the ice slurry inside the water bottle covered with the designed thermal jackets remains at 0.1 °C even after 4 h, which is the average duration of an outfield exercise. Interestingly, the insulation performance of the designed thermal jackets is much better than the commercial insulated water bottles like FLOE bottles and is very competition to that of vacuum flasks for a same period of 4 h and ambient conditions.

Efficiency of the Thermal Jacket on the delivered temperature of prewarmed crystalloid intravenous fluid.

Warming of intravenous fluids can decrease the incidence of hypothermia in surgical patients. A quasi-experimental research design was used to compare the delivered temperature of fluids using a conventional blood warmer and the Thermal Jacket, an insulation device designed for intravenous fluid bags. Fluids were divided into one control and three experimental groups. Fluids were initially either room temperature (22.05 +/- 0.45 degrees C) or prewarmed to 41.45 +/- 1.05 degrees C and infused using no temperature maintenance device, a Thermal Jacket, or a water bath blood warmer. Temperatures were recorded at 10-minute intervals at flow rates ranging from 100 to 1,000 mL/hr. Analysis of variance showed a highly significant difference between the delivered temperatures using the various temperature maintenance devices, as well as varying flow rates. The Thermal Jacket, used with prewarmed intravenous fluids, was as effective as the conventional method of delivering warmed fluids. Also, within the range of flow rates studied, faster flow rates tended to yield higher delivered temperatures.

The influence of the equivalent hydraulic diameter on the pressure drop prediction of annular test section

The flow behaviour and the pressure drop throughout an annular flow test section was investigated in order to evaluate and justify the reliability of experimental flow loop for wax deposition studies. The specific objective of the present paper is to assess and highlight the influence of the equivalent diameter method on the analysis of the hydrodynamic behaviour of the flow and the pressure drop throughout the annular test section. The test section has annular shape of 3 m length with three flow passages, namely; outer thermal control jacket, oil annular flow and inner pipe flow of a coolant. The oil annular flow has internal and external diameters of 0.0422 m and 0.0801 m, respectively. Oil was re-circulated in the annular passage while a cold water-glycol mixture was re-circulated in the inner pipe counter currently to the oil flow. The experiments were carried out at oil Reynolds number range of 2000 to 17000, covering laminar, transition and turbulent flow regimes. Four different methods of equivalent diameter of the annulus have been considered in this hydraulic analysis. The correction factor model for frictional pressure drop was also considered in the investigations. All methods addressed the high deviation of the prediction from the experimental data, which justified the need of a suitable pressure prediction correlation for the annular test section. The conventional hydraulic diameter method is a convenient substitute for characterizing physical dimension of a non-circular duct, and it leads to fairly good correlation between turbulent fluid flow and heat transfer characteristic of annular ducts.