Changes In Design Parameters Research Articles

Annual Energy Consumption Cut-Off with Cooling System Design Parameter Changes in Large Office Buildings

A variety of greenhouse gas reduction scenarios have been proposed around the world to ensure sustainable developments and strengthen the global response to the climate change. To cope with this, it is urgently needed to reduce the amount of energy used for the heating, ventilating, air conditioning, and refrigerating (HVAC&R) systems in large buildings. This study discusses the reduction of cooling energy in large office buildings through the minimization of changes in components and equipment, such as heat source equipment and pumps, changes in the layout and operating methods of chilled water circulation pumps, and changes in the temperatures of chilled and condenser water. To do this, this study targeted an entire cooling system consisting of a hydronic system, a chiller, and a cooling tower, and conducted a quantitative analysis of the energy consumption and of the reduction achieved through a change in the pumping system type in the cooling system and a change in the Korean standard design and temperature of chiller and cooling tower via EnergyPlus simulations. The simulation results showed a cooling energy reduction of 103.2 MWh/yr, around 15.7%, where the primary constant-speed system (Case A) was changed to a primary variable-speed pump (Case B) in the configuration with a chilled water circulation pump. To reduce the cooling energy further, annually 142.3 MWh, around 21.7%, Case C in this study changed the outlet temperature of the chiller and temperature difference from 7 °C, 5 K to 9 °C, 9 K. Finally, when applying a change in the condenser water production temperature from 32 to 23.9 °C in accordance with ASHRAE Standard 90.1 for Case D, a cooling energy saving of 182.4 MWh/yr was observed, which is about 27.8%.

Investigation of sectional operating elements for conveying agricultural materials

The paper covers the results of the theoretical and experimental investigation of the developed sectional operating element of a flexible screw conveyer designed for transporting bulk agricultural materials. In order to determine the correlation between the design parameters of the hinged screw sections and the minimum permissible radius of curvature of a processing line, the analytical dependences have been deduced. The results of the experimental studies aimed at determining the efficiency of a screw conveyer and the level of the grain material damage depending on the change in design, kinematic and technological parameters of an operating element are presented.

Risk assessment of cement placement failure due to cement loss caused by design changes in deepwater well construction

The Well Containment Screening Tool (WCST) has been adopted by deepwater oil and gas operators, in the aftermath of the Macondo/Deepwater Horizon tragedy, to evaluate well integrity during worst-case survival loads. It favors a more conservative deepwater casing scheme with thicker casing walls and, hence, narrower cementing annuli for the same borehole diameters. These design changes may increase the risk of cement loss during narrow-annuli cementing, possibly compromising the cement barrier. Thus, the WCST may actually increase the risk of another well control incident.To examine this possibility, we developed a model to simulate and quantify fluid and cement loss in narrow casing-formation annuli. This model analyzes the influence of design parameter changes, such as a change in casing wall thickness, on generating additional zonal isolation risk in deepwater. Our analysis suggests that a minor increase (within 0.1”) in casing thickness, through increasing outer diameter, has little influence on the risk of cement loss, as does a slight decrease in mean open-hole diameter. Larger increases in casing diameter and reductions in open-hole diameter, however, increase the risk of cement integrity failure, particularly at flow rates above 100 gpm, because of increased cement loss risk, as expected. Beyond the specific problem we analyze, the quantitative risk-analysis approach described here allows for quantification of risk associated with deepwater well design and cementing changes.

Production rates and EUR forecasts for interfering parent-parent wells and parent-child wells: Fast analytical solutions and validation with numerical reservoir simulators

Analytical expressions are given to forecast the production decline and estimated ultimate reserves (EUR) for pairs of both parent-parent wells and parent-child wells. The forecasts use physics-based flow rate quantification in elementary flow cells between hydraulic fractures sets. The intrinsic rate in the flow cells for a given shale formation can be obtained and scaled by a type curve specific for its completion and reservoir parameters. The model then can predict how changes in fracture treatment design parameters will affect the performance of new wells in the same target zone. The effect of well down-spacing and the onset of pressure interference on the performance of parent-parent wells can be forecasted with reasonable accuracy. Similarly, the equations can also predict the effect of infill drilling of child wells on the performance of both well types. The method is applied to real world examples from Eagle Ford acreage. The fast analytical model forecasts are benchmarked against the results from an independent numerical reservoir simulator, with satisfactory matches. The validated approach aims to provide a practical analytical tool for the production forecasting of multi-wells in shale formations.

Investigation of Strip Warpage Behavior in Wire Bonding Process

Abstract This study successfully established a strip warpage simulation model that is applied to the wire bonding process, and explored the effects of structural designs, material types, and processes such as molding, post and mold cure (PMC), pretreatment, and ball mounts on the strip warpage. The error between the experimental values and the simulation values is less than 13.7%. In addition, the Taguchi method is used to determine that the key factors affecting the strip warpage are the die thickness and the mold compound thickness, and that the secondary key factor is the molding temperature. This study concluded that in order to reduce strip warpage, the die thickness must be increased, while the compound thickness and the molding temperature must be decreased. To solve this problem, the structural design criteria proposed in this study use a smaller distance ratio of the neutral axis of the strip (zn) to the dice centroid (zdie). With this modification, it can reduce warpage and overall thickness of the strip. These observations indicate that the proposed model can be used to understand the effects of structural design, material types, and process parameter changes on the strip warpage. Strip design criteria are also provided in order to reduce the strip warpage, and thus, meet the requirement of thin and compact production lines, accelerate product development cycles, improve product quality, and reduce development costs.

A dimension-driven adaptive programming for tool-path planning and post-processing in 5-axis form milling of hyperboloidal-type normal circular-arc gears

Hyperboloidal-type normal circular-arc gears (HNCGs) are a latest application of circular-arc tooth profile in the gearing with perpendicular non-intersection axes, and the existing software programs provided by the original equipment manufacturers (OEMs) for specific machine tools cannot yet directly support the manufacture of HNCGs. In this paper, a dimension-driven adaptive programming methodology is proposed to automatically carry out the tool-path planning and generate the G-code file for the form milling of HNCGs on general 5-axis CNC machine tools. Based on the mathematical model of tooth surface, the basic strategy for 5-axis form milling of tooth is presented, an interference-free tool path considering both roughing and finishing operations is planned, and furthermore, the tool-path data is transformed to achieve the machine tool coordinates. To quickly respond to the changes of design and machining parameters, a dimension-driven adaptive programming software package is developed to automatically compute the tool path, conduct the post-processing, and generate the G-codes for 5-axis form milling of HNCGs with different specifications, and example verification is carried out to demonstrate the validity of the proposed method.

Use of Taguchi DOE for CFD Simulation to maximize the Reusability of Working Fluids of Centrifugal Filter

Centrifugal filtration is a mechanical method of separation which uses centrifugal force and density difference for separation of particles. The paper aims to optimize the filter design in order to maximize the filtration efficiency and increase the reusability of the fluid by varying the input parameters. This is achieved by analyzing the particle behavior using Discrete Phase Modelling and Taguchi approach. The filtration efficiency is found to be significantly enhanced by changes in design and process parameters in the system. Increased efficiency could assure higher quality of fluid, which enhances its reusability.

Learning the basics of a battery pack control system

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source. The main property of a power source with an automatic unloading device of the proposed design, confirmed as a result of a numerical experiment, is that the automatic unloading device provides a clear relay switching of the pump operation mode from unloading to operating mode and vice versa. The revealed properties make it very promising to use a pump-accumulator power source in the hydraulic systems of mobile machines and technological equipment.

Economic and theoretical study of the power supply from a pump-battery based on a discharge machine

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source.

Impact of climate change on pavements

Climate change is reflected in changes in average weather conditions and the more frequent occurrence of extreme conditions. It also affects the field of road transport and shows impacts both on traffic and road users as well as on the road infrastructure itself. The main objective of this work is therefore to evaluate the impact of climate change on the performance of road infrastructure (pavements) and to educe recommendations through proposals for adaptation measures. The impacts of climate change on road infrastructure result in changes in some road design parameters (average temperatures, radiation index, etc.). The different cases of cracking (fatigue or other) are assessed separately using degradation indices for each layer composing a pavement (surface layer, base layer, stabilized layer, etc.)

Review of Substation Grounding System Behavior Under High Frequency and Transient Faults in Uniform Soil

Substations are important parts of electric power systems, and they require well-designed grounding systems. A proper grounding system guarantees the safety of the personnel working in an environment surrounded by grounded equipment from possible electric shock, protects the equipment against unnecessary breakdowns, and conserves the stability of the entire electrical system throughout its operation. Grounding systems developed under power frequency conditions generally react differently under high frequency and transient conditions, such as switching transients and lightning strikes. This work reviews the modeling methods for substation grounding systems and their performance when grounding design parameters change under high frequency and transient fault conditions.

Desain Saluran Terbuka Berbasis Microsoft Excel Perhitungan dan Pemodelan yang Praktis dan Effisien

Saluran dibangun sebagai media yang berfungsi untuk mengalirkan air. Di dalam kegiatan perencanaan, desain, dan konstruksi saluran memerlukan banyak waktu, upaya , dan biaya. Desain dan konstruksi saluran harus sesuai dengan kebutuhan dan karakteristik lokasi yang digunakan. Seringkali terjadi perubahan parameter dalam menentukan desain saluran akibat pertimbangan teknis maupun ekonomis. Hal tersebut menuntut perubahan desain saluran yang sesuai dengan parameter yang baru. Oleh sebab itu, diperlukan alat untuk mempermudah perhitungan desain saluran. Parameter yang diperlukan untuk menghitung desain saluran adalah debit (Q), faktor tahanan Chezy (C), Koefisien Darcy-Weisbach (f), atau faktor kekasaran Manning (n), dan parameter gradien alas saluran (i). Penelitian bertujuan untuk menghitung dan memodelkan desain saluran, serta menyediakan alat atau media praktis dan mudah digunakan. Metode yang dilakukan adalah dengan menerapkan formula perhitungan Chezy, Darchy-Weisbach, dan Manning untuk berbagai bentuk saluran menggunakan perangkat lunak Microsoft Excel. Penentuan nilai faktor tahanan Chezy (C), Koefisien Darcy-Weisbach (f), dapat dihubungkan dari faktor kekasaran Manning (n). Koefisien kekasaran Manning (n) dapat diperkirakan dari ukuran partikel material penyusun alas saluran (d) menggunakan formula, maupun mengacu kepada tabel faktor kekasaran Manning. Penelitian ini menghasilkan alat untuk menghitung dan memodelkan desain saluran terbuka “Kalkulator Desain Saluran – FAR”. Penulis mengusulkan formula baru untuk memperkirakan nilai faktor kekasaran Manning (n) dari ukuran partikel material penyusun alas saluran (d). Selain itu, penulis mengusulkan formula untuk menghitung langsung tinggi air dalam penampang geometri saluran (y). Formula tersebut diperoleh dengan memasukkan koefisien α yang berdasar dari hubungan antar parameter geometri saluran kedalam formula Chezy, Darchy-Weisbach, dan Manning.
 Kata Kunci: alat, desain, geometri, praktis, saluran.

Development and Application of a Novel Metric to Characterize Comprehensive Range of Motion of Reverse Total Shoulder Arthroplasty.

Active range of motion (ROM) of reverse total shoulder arthroplasty (rTSA) can be limited by bony impingement, muscle inability, and joint instability. The aim of this study was to develop a novel metric representative of comprehensive ROM of rTSA, which is evaluated in the context of all three factors. It was hypothesized that the metric, termed global circumduction ROM (GC-ROM), would capture differences resulting from directional changes in rTSA design parameters known to increase ROM. GC-ROM was calculated for a set of 18 rTSA configurations with humeral polyethylene cup depths of 6 and 8.1 mm, glenosphere lateralization (GLat) distances of 0, 5, and 10 mm, and neck-shaft angles (NSA) of 135°, 145°, and 155°. For any implant configuration, arm positions were defined by internal/external (IE) rotation angle and two spherical coordinates representing the elevation plane angle and elevation angle. At each IE rotation angle, incremental positions with variable elevation plane and elevation angles were checked for feasibility based on impingement, muscle ability, and risk of instability. Coordinates of feasible positions were mapped to unit spheres and connected to form regions, of which the surface area was calculated to represent allowable circumduction ROM. ROMs were averaged across all IE rotation angles to produce a single metric, GC-ROM. The results showed that decreasing cup depth and increasing GLat and NSA increased GC-ROM. In conclusion, a novel metric to characterize comprehensive ROM, evaluated based on several ROM-limiting factors, was developed as a performance metric through which rTSA designs can be compared. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:880-887, 2020.

Efficient Variability Analysis of Photonic Circuits by Stochastic Parametric Building Blocks

This paper presents a method to build stochastic parametric building blocks to be used in photonic process design kits. The building blocks are based on parametric macro-models computed by means of the generalized Polynomial Chaos Expansion technique. These macro-models can be built upfront and stored in process design kits. Being parametric, they do not have to be recalculated if the value of their design or statistical parameters change. It is shown that a single deterministic simulation performed with a classical circuit simulator is sufficient to perform the statistical analysis of any arbitrary photonic circuit realized combining these building blocks with different parameters, without the need of time-consuming Monte Carlo approach. Relevant numerical examples are used to demonstrate that the proposed macro-models are truly parametric, inherently stochastic and have greater simulation efficiency compared to Monte Carlo.

Design and Characteristic Analysis of a MEMS Piezo-Driven Recirculating Inkjet Printhead Using Lumped Element Modeling.

The recirculation of ink in an inkjet printhead system keeps the ink temperature and viscosity constant, and leads to the development of a high-performance device. Herein, we propose a recirculating piezo-driven micro-electro-mechanical system (MEMS)-based inkjet printhead that has a pressure chamber, a nozzle, and double restrictors. The design and characteristic analysis are performed using a two-port lumped element model (LEM) to investigate the effect of design parameters on the system responses. Using LEM, the jetting pressure at the pressure chamber, velocity at the nozzle inlet, meniscus pressure, and Helmholtz resonance frequency are predicted and the comparative analysis of the jetting pressure and velocity between LEM and the finite element method (FEM) simulation is conducted to validate our proposed LEM method. Furthermore, the effect of a change in major design parameters on the jetting pressure, velocity, and Helmholtz resonance frequency is analyzed. On the basis of this analysis, the optimized device dimensions are finalized. From our analysis, it is also concluded that the restrictor is more sensitive than the pressure chamber in terms of their variations in depth. As the cross-talk effect can occur due to an array of hundreds or thousands of nozzles, we investigated the effect of a single activated nozzle on the non-activated neighboring nozzles, as well as the effect of multi-activated nozzles on a single central nozzle using our proposed LEM.

Determination of statistical data of conditional probabilities of the technical condition of internal combustion engines when compiling the Bayes diagnostic table

One of attractive methods for in-place diagnostics of internal combustion engines is the method based on using the generalized Bayes formula of conditional probabilities. The article is devoted to the applicability improvement of the Bayes algorithm for assessing the technical condition of internal combustion engines. The use of this algorithm involves the compilation of a diagnostic table, the elements of which are conditional probabilities of selected diagnoses in case of a range of faults. Their relevant determination requires a large amount of statistical data, which is often lacking. To supplement deficient data and increase the reliability of obtained results, the authors propose to use a method for simulating patterns of changes in design parameters of the technical condition of internal combustion engines depending on operating time.

Effect of Helix Angle on the Gear Design Parameters in Helical Gears

Screw compressor demands quite operation. For getting lower noise it is important to have higher contact ratio. Contact ratio can be increased by increasing the Helix angle i .e. indirectly increasing overlap ratio. The paper represents the effect of change in design parameters with respect to helix angle with the keeping same module and same centre distance. Higher helix angle leads lower bending and contact stresses. The study was conducted for screw electrical compressor. Gear was design for fixed parameters except helix angle. Also the contact stresses are analyzed (FEA) on ANSYS. The result from the calculation and FEA are compared for contact stress as well as bending stress.

In Silico Optimization of Femoral Fixator Position and Configuration by Parametric CAD Model.

Structural analysis, based on the finite element method, and structural optimization, can help surgery planning or decrease the probability of fixator failure during bone healing. Structural optimization implies the creation of many finite element model instances, usually built using a computer-aided design (CAD) model of the bone-fixator assembly. The three most important features of such CAD models are: parameterization, robustness and bidirectional associativity with finite elements (FE) models. Their significance increases with the increase in the complexity of the modeled fixator. The aim of this study was to define an automated procedure for the configuration and placement of fixators used in the treatment of long bone fractures. Automated and robust positioning of the selfdynamisable internal fixator on the femur was achieved and sensitivity analysis of fixator stress on the change of major design parameters was performed. The application of the proposed methodology is considered to be beneficial in the preparation of CAD models for automated structural optimization procedures used in long bone fixation.

Application of the Design of Experiments and Computational Fluid Dynamics to Bow Design Improvement

Techniques of the design of experiments (DOE) and computational fluid dynamics (CFD) were applied for improving the bow shape of a tanker hull. Through this, a hull that could reduce the added resistance in waves was derived. The key design elements of the bow shape were selected as parameters for design optimization and added resistance in the short-wavelength region was interpreted through CFD considering the operational condition of the full scale ship. For design parameter changes, the number of analyses was minimized by applying DOE. The regression equation for calculating added resistance was derived using bow-shape design parameters by applying the response surface method and regression analysis to obtain the optimal hull with minimal added resistance was derived. The methodology was applied to an Aframax tanker hull form, and the derived added resistance regression equation and the added resistance value obtained through CFD analysis showed a difference of approximately 1%. The model test results of the improved hull form showed that the added resistance was reduced by 52% in comparison to that obtained for the original hull form.

Two-core fiber-based mode converter and mode demultiplexer

Multicore fibers and few-mode fibers are potential candidates for achieving high-capacity space division multiplexing and mode division multiplexing (MDM) systems. Mode converters are an essential part of any MDM for effectively launching light into the desired mode. Fiber-based mode converters will be more useful than bulk converters because of their compatibility and ease of use. In this contribution, a two-core fiber-based mode converter design is proposed that can effectively convert the fundamental LP01 mode into the LP11 mode by mode coupling. This device can also be used as a demultiplexer in the reverse operation. Such a mode converter can be fabricated by heating a piece of two-core fiber with the thermally diffused core technique. This leads to the diffusion of dopants into the cladding, resulting in an expanded core giving power coupling between the cores. The conversion efficiency of this converter is −0.5  dB at the optimum value. This all-fiber mode converter ensures an extinction ratio of more than 30 dB over 45 nm wavelength, which covers the entire C band. The robustness of the proposed design is analyzed by evaluating the effect of changes in design parameters on the conversion efficiency and extinction ratios.