Effects Of Design Parameters Research Articles

Study on vibration characteristics of anisotropic vehicle rubber bushings by conformal contact force analysis

For ride comfort and handling performance design of vehicles, anisotropic rubber bushings are used as the connection between lower arms and body frames. The nonlinear vibration performance with the deformation amplitude is advantageous to minimise vibration transmission at low magnitude responses and to reduce deformation at large excitations. During transient deformation, the area under the force-deformation curve serves as an indicator for evaluating vibration reduction and isolation performance. The elastomer geometric variables such as the relative radius between the inner and outer contact surfaces are effective design parameters for controlling bushing dynamic behaviour. This study presents a dynamic model to understand the nonlinear stiffness by the contact theory after addressing the actions between elastomer surfaces. The proposed model was confirmed by the measured dynamics stiffness and damping performance. Their influence on the vehicle ride comfort was investigated.

Analysis of airtightness performance of residential areas in Mediterranean climate: Balıkesir houses

Airtightness is one of the crucial physical characteristics of building envelope that affect the building thermal performance and energy consumption. The airtightness of the building is influenced by the quality of workmanship and various design parameters such as window/wall ratio, type of joinery, size of the usage area, wall material, and thermal insulation on the external wall. In this study aiming to determine the airtightness performance of buildings in the Mediterranean climate of Balıkesir houses, airtightness conditions of 43 different houses were determined by blower door test measurement. The air exchange rate (n50) values of 43 houses/residences were obtained between 1.94 and 49.02 h−1 and compared with the current various standards. The effect level of the design parameters on the air tightness of the building envelope was obtained as a result of the analysis performed with analysis of variance and post hoc methods. According to the analysis, joinery type was the most effective design parameter in terms of airtightness, followed by usage area and transparency of facades. The result will help in deciding on the design parameters affecting the airtightness of the building envelope for energy efficiency in the Mediterranean climate.

Identifying effective parameters on capillary tube performance with HCFCs, HFCs blends, and hydrocarbon refrigerants: Numerical assessment

This work offers a comprehensive numerical evaluation of the performance of capillary tube utilizing different refrigerants, including HCFCs, HFCs blends (Zeotropic, Azeotropic), and hydrocarbon, such as such as R22, R404A, R407C, R410A, R507A, and R290 refrigerants to predict the critical length of the adiabatic capillary tube. Utilizing a comprehensive thermodynamic model is applied to simulate the behavior of different refrigerants. Moreover, the effective design parameters based on the internal diameter for the adiabatic capillary tube (ACT), inside surface tube roughness, degree of subcooled, metastable region, condenser diameter, design of evaporator pressure (at critical length), condenser operating pressure, and refrigeration capacity are considered. The numerical model is developed based on the governing equations for mass, momentum, and energy, while a specified empirical equations are employed to represent each of the friction factor for single-and-two phase flow and metastable region. The results showed that the longest length of the ACT of 10.5 m revealed with R410A at mass flow rate of 8 g/s compared with 0.25 m at mass flow rate of 16 g/s for R290. Also, the results showed that the minimum value of friction factor of 0.0189 for R410A compared with maximum value of 0.0208 for R407C. The developed model is validated with available experimental results and models under different operation conditions and is found expectable with a good agreement. Where the standard error for different refrigerant with range value between (2.774% to 3.677%). However, the model represents accurate prediction the flow behavior and the thermal performance of the ACT.

Exergoeconomic assessment of a multi-section solar distiller coupled with solar air heater: Optimization and economic viability

This study focuses on optimizing the solar distiller and provides a foundation for future research and development in solar distillation technologies. This paper does an exergoeconomic analysis of a multi-section solar distiller (MS-SS) system that is combined with a solar air heater (SAH). Therefore, its objective is to determine the most effective operational and design parameters while taking into account the system's lifespan and interest rate. This will offer significant knowledge for improving the MS-SS. Key parameters examined in the study include exergoeconomic indicators, exergy production factor (EPF), exergy-based loss rate, exergy efficiency, and water cost. Variations in exergy loss rate across different seasons were observed, with implications for system efficiency. The exergoeconomic analysis demonstrates the impact of interest rates on the system's economic viability, with corresponding effects on water costs. The key findings suggest varying daily output and exergy efficiency, with the lowest values recorded in winter and the highest in summer. Summer demonstrates superior output exergy, averaging of 145 × 103 Wh per month. In the normal case of output salinity between 0 and 500 ppm, the cost was reduced by 96.7 %, and by 96.3 % in the case of four interior sections. Water cost reduction is also observable at the same output salinity, with 54.1 % at 0 ppm and 62.4 % at 200 ppm between number of interior sections = 0 and 4.

Comprehensive review on ideas, designs and current techniques in solar dryer for food applications.

Due to the expansion of residents, the consumption of non-renewable energy increased enormously, thus indirectly increasing pollution and affecting the surroundings. To reduce pollutions in the surroundings, it is recommended to choose non-conventional energy sources. By satisfying this, we can probably decrease the non-renewable sources of energy, by consuming the solar power in day-to-day life in the application of food drying process. In this review article, we have discussed the classification of solar dryer and the impact of design modifications performed in the components of solar dryer and assessed the various types of solar dryer performance, cost estimations and designs performed in solar dryer of food applications which were not discussed in the earlier research. The primary and critical task in designing the solar dryer is to achieve higher efficiency at minimum cost. Hence, proper analysis of drying application, selection of suitable components and suitable design must be carried out to attain efficient dryer. Considering these characteristics, this paper primarily focuses on the effective design parameters incorporated with various efficiency enhancement processes of the solar dryer in the applications of food drying techniques. Thus, this review paper delivers the various classifications, design parameters, performance enhancement methods, properties and valuable assets of solar dryer, which helps to develop the sustainable green eco-friendly environment most primarily, in the application of food drying process. This review article concreted the way for upcoming considerations and provided the techniques for the studies to convey the work for promoting method enhancements.

Dendritic propagation on circular electrodes: The impact of curvature on the packing density.

The dendritic growth in rechargeable batteries is one of the hurdles for the utilization of high energy-density elements, such as alkaline metals, as the electrode. Herein we explore the preventive role of the curved electrode surface in the cylindrical electrode design versus the flat geometry on the stochastic evolution of the dendritic crystals. In this regard we establish a coarse-grained Monte Carlo paradigm in the polar coordinates (r,θ), which runs in a larger scale of time and space (∼μs,∼nm ) than those of interionic collisions (∼fs, Å). Subsequently we track the density and the maximum reach of the microstructures in real time, and we elaborate on the underlying mechanisms for their correlation of the relative dendrite measure with the electrode curvature. Such quantification of the positive impact of the curvature on suppressing dendrites could be utilized as an effective longevity design parameter, particularly for the cases prone to dendritic propagation.

Numerical Investigation of Cross-Flow Water Cooling Towers

Abstract In this study, thermal performance of the forced cross-flow water cooling tower is numerically investigated by using the commercial computational fluid dynamics software ansys-cfx. The temperature variation between inlet and outlet of the water, namely, process water temperature, is the main extracted result of simulations. Additionally, the cooling range (CR) that is the difference between inlet water temperature and outlet water temperature is the second representative result of the analysis. The effect of air velocity (Va), water droplet diameter (dw), and water temperature at the inlet of tower (Tw) are the variables that are considered to be the effective design parameters on the process temperature of the water. The process water temperature decreases, but the cooling range increases when the air velocity increases. When the inlet water temperature increases, the process water temperature and the cooling range also increase. On the other hand, the process water temperature decreases with the decreasing diameter of water droplets.

Design of Localized High-Concentration Electrolytes via Donor Number

Salt-concentrated electrolytes offer properties beyond conventional dilute electrolytes yet suffer from high cost and viscosity which hinder their practical applications. Introducing a secondary solvent as a diluent could reduce the salt content while maintaining the local solution structure of salt-concentrated electrolytes, giving rise to localized high-concentration electrolytes (LHCEs). Through a comprehensive investigation involving over 500 samples, we find that the dielectric constant of solvent, a widely used parameter for electrolyte design, does not serve as a useful screening criterion for diluents; instead, donor number (DN) is an effective design parameter to achieve LHCE structure─i.e., the primary solvent must have DN > 10 and the diluent must have DN ≤ 10. Based on this simple rule, a new LHCE using low-cost m-fluorotoluene diluent is formulated, enabling high-voltage (>4.6 V) and wide-temperature (−40–100 °C) operation of lithium batteries.

Molecular DNA dendron vaccines

A foundational principle of rational vaccinology is that vaccine structure plays a critical role in determining therapeutic efficacy, but in order to establish fundamental, effective, and translatable vaccine design parameters, a highly modular and well-defined platform is required. Herein, we report a DNA dendron vaccine, a molecular nanostructure that consists of an adjuvant DNA strand that splits into multiple DNA branches with a varied number of conjugated peptide antigens that is capable of dendritic cell uptake, immune activation, and potent cancer killing. We leveraged the well-defined architecture and chemical modularity of the DNA dendron to study structure-function relationships that dictate molecular vaccine efficacy, particularly regarding the delivery of immune-activating DNA sequences and antigenic peptides on a single chemical construct. We investigated how adjuvant and antigen placement and number impact dendron cellular uptake and immune activation, invitro. These parameters also played a significant role in raising a potent and specific immune response against target cancer cells. By gaining this structural understanding of molecular vaccines, DNA dendrons successfully treated a mouse cervical human papillomavirus TC-1 cancer model, invivo, where the vaccine structure defined its efficacy; the top-performing design effectively reduced tumor burden (<150 mm3 through day 30) and maintained 100% survival through 44 d after tumor inoculation.

Stability issues for elastomeric bearings: analytical formulations compared to experimental results

During earthquake strong motions, anti-seismic devices are subjected to large horizontal deformations combined to vertical stress due to gravity loads. For elastomeric bearings, the most widespread technology used to this aim, it is necessary to value critical load capacity under this combined effect, to ensure their stability in service. In this paper, elaborations of data from experimental campaign on full-scale rubber bearings (HDRBs) are compared to results form a brief theoretical overview, to evaluate their stability limits. To examine the effect of device geometrical characterization on bearing mechanical behavior, to check instability mode and to evaluate the interaction between vertical pressure and shear deformation, three different types of full-scale devices have been considered (ϕ500, ϕ600, ϕ700). Experimental data refers to “soft” natural rubber bearings, having a shear modulus G= 0.4MPa (at γ=100%), an equivalent damping factor ξ = 10÷15, a primary shape factor S1 varying in the range [19,44 – 22,72] and a secondary shape factor S2 varying in the range [2,8÷3,4]. Data derive from static shear tests, at increasing levels of shear strain (up to γ = 250%) combined to growing compressive stress (from 6 MPa to 20 MPa). Their elaboration has been accompanied by the use of dimensionless factors, in particular the ratio γ/S2, that results an effective design parameter to describe bearing performance. On the base of analytical formulations from literature, the experimental results have been matched with theoretical evaluations of the critical load. The experimental occurrence of buckling instability has been read also in light of design guidelines provided for rubber devices.

Effect of design parameters on passive control of heat transfer enhancement phenomenon in heat exchangers–A brief review

The development of innovative heat exchangers with improved heat transfer performance is an important concern for heat transfer applications. The use of passive techniques such as vortex generators, surface roughness, augmentation of heat transfer area, or the combination of passive techniques is effective to improve the performance of heat exchangers. This review briefly summarizes the passive heat transfer enhancement techniques and the most important types of heat exchangers. Many effective design parameters have been briefly discussed to improve the performance of passive heat transfer techniques for heat exchangers.

Justification of the design parameters of the blade of the rotary working body of the solid fertilizer spreader

BACKGROUND: Organic, mineral and organomineral fertilizers in both granular and powder form are used in agricultural production in order to increase of soil fertility significantly, as well as to replenish soil reserves of micro-, meso- and macroelements. For fertilizer screening on a surface of a field, agricultural producers use machines with centrifugal-type working bodies which have horizontal or vertical rotation axis. In pursuance of the task of reducing the shift time consumption, a number of researchers find it reasonable to use a low-frame design of the machine to make direct loading of it from the dump truck body possible. For machines, having such design, rotary spreading working bodies with blades on a horizontal rotation axis are the most suitable.&#x0D; AIMS: The article is concerned with the justification of the design parameters of the blades of the rotary spreading working body of the low-frame body spreader of solid mineral and organomineral fertilizers.&#x0D; METHODS: The length of the working surface of the rotor blade with a horizontal rotation axis is justified theoretically for the most uniform distribution of solid fertilizers. An example of calculating the length of the blade of such a device based on the previously established overall dimensions of the spreader is given.&#x0D; RESULTS: On the basis of experimental data, the expediency of using trough-shaped blades with a length of 110 mm was confirmed. The most effective design parameters of the dimensions of the rotor blades for screening fertilizers were established, taking into account the reduction of possible options for fertilizer granules crushing by means of preventing their recirculation inside the rotor casing. The relevance of research of devices with rotary working bodies on horizontal axes of rotation is argued.&#x0D; CONCLUSIONS: Possible prospects for future research and the possibility of further improvement of the low-frame granular fertilizer spreader are proposed.

AN EMPIRICAL APPROACH TO DESIGN A PIFA ANTENNA

Abstract: A parametric study is performed on a Planar Inverted F Antenna (PIFA) that operates at the frequency of 900 MHz The effect of the variation of the parameters on the bandwidth (BW) is analyzed. The study is performed using the Finite Element Method (FEM) numerical technique and the High Frequency Structural Simulator (HFSS) software.Regression analysis is applied on the data obtained from the simulation to present a mathematical model that estimates the fractional bandwidth FBW. An empirical equation that predicts the FBW of the PIFA is introduced. The equation uses the effective designparameters; substrate material thickness and ground plane dimensions as predictors. A comparison between the results calculated by the equation and the results obtained via simulation is carried out for validation purposes. The results are found to be very close except for the values corresponding to substrate thicknesses above 6mm. Moreover, a second simulator using a different numerical technique is used for further verification.A PIFA that operates at the 900 MHz frequency is fabricated. The results obtained from the physical measurement are compared with the results calculated by the empirical equation and the results obtained from the simulation. Close compatibility is observed.

An eco-friendly reliability-based design optimization of intermediate reinforced concrete moment frames

Failing to account for the stochastic nature of structural parameters such as material properties, external loads and geometric dimensions, can cause uncertainty about the safety of the design of an engineering structure; thus, assessing the reliability of a design seems necessary. The present study considered uncertainty related to the statistical nature of the parameters affecting the design of intermediate reinforced concrete (RC) moment frames in the process of achieving an optimal design. The reduction of CO2 emissions, which comprises a large percentage of greenhouse gas emissions, also must be considered from an environmental perspective in the design and construction of RC structures. Hence, an objective function was formulated that also minimizes CO2 emissions. In the objective function, the effective design parameters with probabilistic distributions have been considered when calculating the reliability index using the Monte Carlo simulation method. The limit state functions also are taken into account according to the design requirements in ACI 318-19. Ultimately, the performance of the formulated objective function in the reliability-based design optimization of four-story and nine-story intermediate RC moment frames is presented using four metaheuristic algorithms.

THERMAL PERFORMANCE OF VERTICAL SHAFTS IN BUILDINGS: AN OVERVIEW OF EFFICIENT DESIGN PARAMETERS

There are indications that buildings that include vertical shafts can affect the ‎performance of buildings. Many ‎Publications in major peer-reviewed journals from different fields ‎‎(energy and buildings) were found using various ‎keywords (Air shaft, light well, vertical shaft, thermal performance, etc.). The review of previous studies was on the role of natural ventilation in vertical shaft buildings in different climates, efficient design parameters, and their application to improve thermal performance and decrease energy consumption. These parameters include various vertical shaft configurations and components such as vertical shaft geometry, opening characteristics, roof properties, and materials. The height, length, and width of vertical shafts significantly impact indoor thermal conditions and energy consumption. The second effective design parameter was the openings, which strongly influence air velocity, air pattern, airflow, air temperature, and ventilation rate.

A new biomass gasification driven hybrid system for power and liquid hydrogen cogeneration: Parametric study and multi-objective evolutionary optimization

The purpose of this paper is focused on introducing a new layout of an electricity and liquid hydrogen cogeneration power plant and evaluating its performance from the exergo-economic and environmental stand points. The system is based on the combination of a biomass gasification gas turbine cycle, a Rankine cycle, an electrolyzer unit, and a hydrogen liquefaction cycle. A parametric model is firstly developed to study the sensitivity of the system performance on the main design parameters (including biomass flow rate ṁbiomass, gas turbine inlet temperature TGT, compressor pressure ratio PR, and steam turbine inlet pressure PSRCT). Afterward, the optimal operation of system is selected using by a multi-objective optimization approach. The observations revealed that m˙biomass is the most effective design parameter. The optimal design parameters are obtained as ṁbiomass = 1.94 kg/s, TGT = 1421 K, PR = 5.52, and PSRCT = 3886 kPa, which results in the maximum electricity and hydrogen production of 3377 kW and 14.8 kg/h together with minimum total cost rate of 86.61 $/h. At this condition, the optimal environmental index is 1.09 kgCO₂/kWh.

PREVENTION OF HYDRODYNAMIC INSTABILITY CONDITIONS IN SAFETY SYSTEMS WITH PUMPS OF NUCLEAR POWER PLANTS

The study of hydrodynamic instability in the safety systems of nuclear power plants is relevant. In the deterministic analysis of the safety of nuclear power plants based on accident simulation, it is necessary to take into account the possibility of hydrodynamic instability in the operational and transient modes of safety systems. The consequences of the emergence of hydrodynamic instability in safety systems can be following: a significant deterioration of the heat and mass exchange conditions in the reactor and steam generators during the heating process, an increased power of thermo-hydro-shock on the equipment of the nuclear installation and other negative effects. The negative consequences of the hydrodynamic instability in the safety systems of nuclear power plants can be a significant deterioration in the conditions of heat-mass exchange and the thermal water hammers with increased power. The main reasons for the hydrodynamic instability in safety systems are inertial lag in the response of control valves and head-flow characteristic of pumps to “fast” changes in hydrodynamic parameters in nuclear power plant systems. The purpose of this work is to determine methods for minimizing the impact of the causes of hydrodynamic instability in security systems. The methods of substantiating effective structural and technical parameters of damping devices to prevent conditions of hydrodynamic instability in stationary working and transient modes of safety systems with pumps are given. A method for substantiating effective design and technical parameters of damping devices to prevent conditions of hydrodynamic instability in transient modes of starting pumps of safety systems is presented. Stability conditions in stationary operating modes of the initial steam-gas volume of damping devices are determined. The minimum permissible dimensions of damping devices that meet the conditions of hydrodynamic stability in the transient modes of SB pumps are determined.

Design, analysis and prototyping of a spherical drone for underground mines

This paper aims to provide performance optimisation of a multirotor drone that is designed for underground spaces. Currently, drones are being used efficiently for various applications in surface fieldwork projects. But using drones for underground spaces is challenging because of confined space, GPS-denied environment and various air properties in underground spaces. In this paper, first, the designed and manufactured drone is discussed. Then, to improve the drone performance for defined missions, a sensitivity analysis is done over the effective design parameters of the drone components and air density as an environmentally effective parameter. The sensitivity analysis over the flight simulations shows that drone performance increases by increasing air density, while the optimised number of propellers blades is presented. The results show that by increasing the battery capacity, the flight time increases but the overall performance of the drone decrease. Also, the drone would be able to carry about 450 grams payload and payloads more than 450 grams can significantly decrease flight time. Finally, the results of sensitivity analysis lead to optimise the drone performance efficiently for the designed mission in underground mines.

Daylight performance of toplighting: An overview

Novel and advanced daylighting strategies and systems can noticeably decrease artificial lighting consumption and considerably improve light quality in the interior environments. In modern architecture, employment of rooflights is prevalent since they transmit daylight into deep plans or spaces lacking facade. Although, the use of this system is more common in temperate and cold climates, because of its severe thermal effects, it can be used in all the climates by innovative design strategies. Proper design of rooflights can significantly reduce energy use of lighting, heating, and cooling. Accordingly, the present study was designed to present an overview of toplighting field surveys conducted between 1984 and 2021. In this review study, analytical methods, efficient design parameters, and their effects on daylight and energy performance of the rooflights were investigated. These parameters include rooflight and indoor environmental conditions. Reviewed studies have utilized various methods such as analytical formulae, computer simulation, and experimental designs to investigate performance of the rooflight. The key point is finding or designing a proper state of toplighting in order to increase energy efficiency of the building while improving visual comfort. Also, studying effective rooflight design parameters presents practical guidelines for future studies.

Systematic evaluation of effects of recycled materials and mix design parameters on the rutting and cracking performance of asphalt mixes

Problems associated with the rutting and cracking of asphalt mixes call for the use of balanced mix design and thus have received close attention from researchers and practitioners. The increased use of recycled materials, such as recycled asphalt pavement (RAP) and recycled asphalt shingles (RAS), further complicates the performance of asphalt mixes. Most studies of RAP and RAS have focused on the inclusion of these recycled materials in asphalt mixes designed for research purposes, which could differ from mixes designed by contractors for practical use. Therefore, a systematic review is needed of the effects of recycled materials and mix design parameters on the rutting and cracking performance of mixes designed by contractors. In addition, contractors need guidance in developing asphalt mixes that meet specifications that require rutting and cracking tests instead of simply relying on trial and error. To address these needs, in this study, rutting and cracking tests of forty contractors’ asphalt mix designs were conducted and the most effective design parameters on the performance of asphalt mixes were presented and discussed. These mixes included different percentages of RAP or RAP/RAS, performance grades of binders, design gyration numbers, aggregate gradations, and other volumetric properties. The provided results and discussions can be used as guidance for contractors to improve their mix designs to meet specifications.