Detailed Design Approach Research Articles

Indigenous Development of MIC-Based C-Band Dual Chain Down Converter Unit for GEOSAT- Spacecraft Checkout System

As part of miniaturization, the development work for the C-band dual-chain down converter, which is extensively used in TM (Telemetry) data acquisition system in GEOSAT spacecraft checkout system has been taken up in MIC (Microwave Integrated Circuit) approach using microstrip line structure. A prototype unit is realized using standard surface mount devices (SMD) and few indigenously developed MIC components namely, the directional couplers, the power dividers etc. The MIC-based down converter module, which forms the heart of the unit is housed in an Aluminium milled box having the dimension of 150 x 150 x 25 mm3. Except internal Local Oscillator (LO), RF Switches and Power supply, all other circuitry are mounted withinthis milled box which is housed in 1U chassis. It meets all the requirements of a conventional down converter. The paper describes the salient features of the unit, its detailed design approach and realization plan and finally the test and evaluation results of the prototype unit developed indigenously.

Design approach of thrust-matched rotor for basin model tests of floating straight-bladed vertical axis wind turbines

Rotor redesign approaches have been widely proposed to solve the thrust mismatch issue caused by scaling effects for basin model tests of horizontal axis floating wind turbines (FWTs). However, limited basin model tests utilized the thrust-matched rotor (TMR) to accurately evaluate the aerodynamic loads applying to the vertical axis FWTs. This paper described the detailed design approach of the TMR of floating straight-bladed vertical axis wind turbines (VAWTs) with a rated power of 5.3 MW. First, the AG455 airfoil was selected to replace the NACA0018 airfoil. AG455 airfoil can show a larger lift coefficient and a smaller drag coefficient at low Reynolds number. On this basis, the load distribution match algorithm was used to assign the blade pitch angle and chord length at each section of the blade. This method takes the spanwise load and load change rate of model-scaled blade and full-scaled blade as the constraint conditions. By adopting this method, the rotor thrust can be tailored to match the prototype values across a wide range of tip speed ratios. This design approach proves advantageous in assessing the aerodynamic performance of VAWTs under varying inflow wind speeds and unsteady wind conditions. The redesigned TMR model under low Reynolds number can meet Froude similarity criterion, which is helpful to improve the accuracy of vertical axis FWT model tests in the wave basin.

Enhancing gas production through advanced detailed design engineering: a global perspective on industry practices

Enhancing gas production through advanced detailed design engineering has become a pivotal approach in the global energy sector. This paper explores the integration of cutting-edge engineering methodologies to optimize gas production processes, reduce operational inefficiencies, and meet increasing energy demands. The application of detailed design engineering in gas production involves sophisticated modeling, simulation, and analysis of production systems, ensuring enhanced precision, safety, and scalability. By leveraging advanced computational tools, engineers can predict and mitigate potential production bottlenecks, optimize well designs, and implement efficient gas processing techniques. The global perspective on industry practices highlights regional variations in design standards, regulatory frameworks, and technological adoption. For example, North American gas fields utilize integrated digital twins and automation technologies to streamline production, while regions like the Middle East emphasize design optimization in offshore gas extraction. Additionally, the development of sustainable practices, such as carbon capture and storage (CCS) and energy-efficient processing units, is becoming a critical focus for gas producers striving to reduce environmental impact and align with international climate goals. This study also examines the role of collaborative frameworks between engineering teams and production operators in fostering innovation and knowledge transfer, further driving the refinement of detailed design approaches. The future of gas production will depend significantly on advancements in materials science, data analytics, and artificial intelligence, which are expected to revolutionize the design and operation of gas production systems. In conclusion, enhancing gas production through advanced detailed design engineering offers the potential to unlock new efficiencies, improve safety standards, and contribute to global energy security. However, the successful implementation of these practices requires continuous investment in research, technology, and cross-industry collaboration.

Autonomous Flight Test of a Novel Nonconventional Biplane Micro Air Vehicle

This paper presents detailed mathematical modeling, controller design, and flight test results for the autonomous mission of a nonconventional fixed-wing biplane micro air vehicle (MAV) called Skylark having span and chord length within 150 mm. Although numerous fixed-wing MAV designs are reported in the open literature, an MAV’s reliable autonomous flight is still a challenge. The primary difficulties in performing the autonomous mission of fixed-wing MAV are system integration within the weight and power budget, center of gravity (CG) management, and flight controller design for fast dynamics. In this paper, the key challenges are addressed by using the higher payload capacity of Skylark, suitable selection and design of avionics components, and design of controller after detailed development of the mathematical model, including the additional effect of propeller wash and motor countertorque. An autonomous flight test is successfully demonstrated after the validation of algorithms and software architecture through nonlinear six-degrees-of-freedom simulation. The detailed design and development approach will increase the MAV’s performance and reliability in civil and military applications.

A new detailed loss model and design approach for LLC resonant converter with phase shift control to overall optimization of converter loss at whole battery charging process

AbstractThis paper proposes a new loss modeling and design method for phase shift controlled resonant LLC converter with optimization applied to minimize the overall loss during the whole battery charging process. In this work, the loss model has been formulated more accurately for phase shift controlled LLC converter. One of the contributions in accurate loss modeling is all switching modes of power switches have been investigated in detail in the aspect of zero voltage switching (ZVS) and ZCS occurrence and their related dynamic loss are updated in loss calculation during the whole charging process. In addition, to optimize the copper and core losses of high‐frequency transformer and resonant inductor, a design trend is included in optimization process to calculate the best physical dimensions and winding parameters of magnetic components. A genetic algorithm has been employed for the optimization during the charging process. In this work, the first harmonic approximation (FHA) model was developed and solved by nonlinear Newton–Raphson method in any operating point along one complete charging process. The target of optimization was designing a wall mounted type level 2 battery charger (7.4 kw/32A) for charging a battery pack with specs according to the Nissan Leaf 2011 electric vehicle. For verification of the proposed method, simulation results are provided and also experimental results for a low‐scale prototype are proposed. In this study, the average efficiency along the overall charging process obtained up to 95% in simulation and 84% in experiments.

Design and Simulation of a Novel Magnetic Microactuator for Microrobots in Lab-On-a-Chip Applications

This article presents the design of a magnetic microactuator comprising soft magnetic material blocks and flexible beams. The modular layout of the proposed microactuator promotes scalability towards different microrobotic applications using low magnetic fields. The presented microactuator consists of three soft magnetic material (Ni-Fe 4750) blocks connected together via two Polydimethylsiloxane (PDMS) semi-circular beams. A detailed design approach is highlighted giving considerations toward compactness, range of motion and force characteristics of the actuator. The actuator displacement and force characteristics are approximately linear in the magnetic field strength range of 80-160 kA/m. It can achieve maximum displacements of 111.6 µm (at 160 kA/m) during extension and 10.7 µm (at 80 kA/m) during contraction under no-load condition. The maximum force output of the microactuator, computed through a contact simulation, was 404.3 nN at a magnetic field strength of 160 kA/m. The microactuator achieved stroke angles up to 18.4 in a study where the microactuator was integrated with a swimming microrobot executing rowing motion using an artificial appendage, providing insight into the capabilities of actuating untethered microrobots.

Robust and low‐cost design of LLC‐type DC transformer in hybrid AC / DC nano‐grids to improve energy conversion ability

In the hybrid AC/DC nano-grid, the LLC-type DC transformer (DCT) is widely utilized in the DC and AC bus connection system (BCS) with high frequency to improve the system power density. However, it always employs the simple open-loop scheme for not increasing the control complexity of the nano-grid system, which creates a big challenge on the inherent features of the DCT circuit for the energy efficiency and conversion ability. Therefore, a robust and low-cost design approach of the LLC-type DCT is put forward in this paper based on the specific requirements of hybrid AC/DC nano-grid. First of all, the design challenges of the LLC-type DCT are discussed by analyzing the functions of BCS in nano-grid application. Then, the detailed parameter design approach is presented step-by-step to meet the energy efficiency and conversion requirements in the full power range. Finally, a 6 kW nano-grid prototype is established to verify the effectiveness of the proposed design method. The results show that the designed DCT can enjoy good energy efficiency and conversion ability with simple control and hence accommodate the high-frequency nano-grid application.

Analysis, control, and modeling of the three‐port converter without port voltage constraint for photovoltaic/battery system application

AbstractFor a photovoltaic (PV)/battery power system consisting of PV module, energy storage system, and local load, using a three‐port converter (TPC) instead of several single‐input converters is more desirable, such as simpler circuit, higher efficiency, lower cost, and centralized control without communication circuit. In this paper, a TPC is proposed and analyzed, which includes operating modes, steady‐state performance, and parameter design. Compared with other converters, the proposed TPC has a low cost, compact structure, and a more flexible voltage relationship among all ports. Moreover, energy management and control methods are further proposed for PV/battery systems based on the proposed converter, which can achieve maximum power point tracking (MPPT) of PV module and constant output voltage. In order to design the control loop and realize multivariable optimal control, a small‐signal model of the converter is obtained in each operation mode. Then a detailed decoupling design approach based on a small‐signal model is provided to allow a separate controller design for the proposed converter. Finally, the validity of the proposed converter and its energy management and control method are verified by experimental results.

4-MW Class High-Power-Density Generator for Future Hybrid-Electric Aircraft

This article describes the underpinning research, development, construction, and testing of a 4-MW multithree phase generator designed for a hybrid-electric aircraft propulsion system demonstrator. The aim of the work is to demonstrate gravimetric power densities around 20 kW/kg, as required for multi-MW aircraft propulsion systems. The key design choices, development procedures, and tradeoffs, together with the experimental testing of this electrical machine connected to an active rectifier, are presented. A time-efficient analytical approach to the downselection of various machine configurations, geometrical variables, different active and passive materials, and different thermal management options is first presented. A detailed design approach based on the 3-D finite element analysis (FEA) is then presented for the final design. Reduced power tests are carried out on a full-scale 4-MW machine prototype, validating the proposed design. The experimental results are in good agreement with simulation and show significant progress in the field of high-power-density electrical machines at the targeted power rating.

Design and performance analysis of 1KW ORC turboexpander with R245fa as working fluid

Organic Rankine Cycle (ORC) is a reliable technology to utilize low and medium thermal energy and has been in development since the beginning of the 19th century and has rapid development in the last few decades. There are a couple of ways to optimize ORC. One of them is to develop an optimized turboexpander. This paper will explain in detail the preliminary and detailed design approach used to design turboexpander for 1kW ORC with R245fa as working fluid. The numerical simulation was performed using ANSYS CFX with turbulence model of Eddy Viscosity Reynold Shear Stress and Aungier Redlich-Kwong Equation of state to predict the material properties. A couple of adjustments had been made when deciding the rotor thickness and blade number, as the proposed method was not able to produce reasonable geometry. The CFD result of the preliminary design has 4.79% less efficiency and 22.7% less power produced than the 0D design. The off-design parameters of 16 Blade number, 20000 rpm, and mass flow of 0.32 kg/s able to produce power 1.38 kW with the efficiency of 76.44%

Design and analysis of a multi-agent e-learning system using prometheus design tool

Agent unified modeling languages (AUML) are agent-oriented approaches that supports the specification, design, visualization and documentation of an agent-based system. This paper presents the use of prometheus AUML approach for the modeling of a Pre-assessment System of five interactive agents. The Pre-assessment System, as previously reported, is a multi-agent-based e-learning system that is developed to support the assessment of prior learning skills in students so as to classify their skills and make recommendation for their learning. This paper discusses the detailed design approach of the system in a step-by-step manner; and domain knowledge abstraction and organization in the system. In addition, the analysis of the data collated and models of prediction for future pre-assessment results are also presented.

Design and analysis of a multi-agent e-learning system using prometheus design tool

Agent unified modeling languages (AUML) are agent-oriented approaches that supports the specification, design, visualization and documentation of an agent-based system. This paper presents the use of prometheus AUML approach for the modeling of a Pre-assessment System of five interactive agents. The Pre-assessment System, as previously reported, is a multi-agent-based e-learning system that is developed to support the assessment of prior learning skills in students so as to classify their skills and make recommendation for their learning. This paper discusses the detailed design approach of the system in a step-by-step manner; and domain knowledge abstraction and organization in the system. In addition, the analysis of the data collated and models of prediction for future pre-assessment results are also presented.

Design Methodology of Centrifugal Automatic Decompression System in Small Gasoline Engine

<div class="section abstract"><div class="htmlview paragraph">This paper deals with designing methodology of centrifugal type automatic decompression system (CADS) for small gasoline engine. CADS reduce the operator’s fatigue to start the engine. When engine cranked, CADS releases combustion pressure of the engine via opening of exhaust valve momentarily during compression stroke, which drastically reduces the hand pulling force required to start the engine with recoil starter unit. A 172 cc gasoline engine, which has applications in agricultural purposes, has been used for designing and development of CADS, which has to be installed at camshaft cam gear assembly of engine. With the new developed concept operator’s hand pulling force for starting the engine has been reduced to 41 % and henceforth durability of engine starting system increased significantly. In this paper detailed design approach has been discussed of working model of CADS. Based on predicted failure modes and generated RPN values, design calculations were carried out for various geometrical parameters of sub parts of CADS like mass of centrifugal flyweight, number of coils, wire diameter, spring rate of torsion spring. PTC CREO 3.0 has been used to make rough 3 D model of assembly and further it is optimized based on calculated design values and ease of manufacturability. A testing approach also has been discussed for checking desired spring rate of torsion spring and on engine overall working mechanism of CADS.</div></div>

Flexural and Shear Tests on Reinforced Concrete Bridge Deck Slab Segments with a Textile-Reinforced Concrete Strengthening Layer.

Many older bridges feature capacity deficiencies. This is mainly due to changes in code provisions which came along with stricter design rules and increasing traffic, leading to higher loads on the structure. To address capacity deficiencies of bridges, refined structural analyses with more detailed design approaches can be applied. If bridge assessment does not provide sufficient capacity, strengthening can be a pertinent solution to extend the bridge’s service lifetime. For numerous cases, applying an extra layer of textile-reinforced concrete (TRC) can be a convenient method to achieve the required resistance. Here, carbon fibre-reinforced polymer reinforcement together with a high-performance mortar was used within the scope of developing a strengthening layer for bridge deck slabs, called SMART-DECK. Due to the high tensile strength of the carbon and its resistance to corrosion, a thin layer with high strength and low additional dead load can be realised. While the strengthening effect of TRC for slabs under flexural loading has already been investigated several times, the presented test programme also covered increase in shear capacity, which is the other crucial failure mode to be considered in design. A total of 14 large-scale tests on TRC-strengthened slab segments were tested under static and cyclic loading. The experimental study revealed high increases in capacity for both bending and shear failure.

Mechanism and experimental validation of innovative self‐centering conical friction damper

Past earthquakes have shown that traditional structural design relies on the component ductility to dissipate the earthquake energy. This has led to significant damage for the structure. Innovative energy dissipation devices have been developed in the past to dissipate the earthquake energy. However, the big disadvantage of traditional energy dissipation devices is the lack of self-centering capabilities. This results to significant residual deformation, which can significantly affect the building resilience. Failing to eliminate the residual deformation can lead to prolong downtime and significant financial losses. In this paper, a novel damper named self-centering conical friction damper (SCFD) is proposed. SCFD utilizes conical surfaces and posttensioning tendons to resist the earthquake loads in all directions. The conical surfaces force the SCFD to self-center, making the SCFD highly desired for earthquake applications. In this paper, detailed mechanical behavior for the SCFD is presented. The hysteresis behavior was verified through the experimental tests. The result shows that the proposed theoretical equations can predict the hysteresis response of the SCFD well. Using the derived equations, detailed parameter study including the influences of pretension forces, effective stiffness of posttension tendons, slope angle, and friction coefficients have been investigated. Results show that the hysteresis behavior can be achieved using different combinations of the slope angle, Pretension (PT) tendons, and friction coefficients. Overall, high slope and friction coefficients will lead to highly efficient SCFD with lower demands on the PT tendons. Detailed design approaches have been presented, which allows the engineers to design SCDF for different applications.

420-GHz terahertz SIW slot antenna with quartz superstrates in silicon technology

To meet the needs of terahertz imaging and communication, a 420-GHz on-chip antenna (OCA) with high gain and high radiation efficiency is designed using a standard 55 nm CMOS technology. In the proposed OCA structure, the substrate integrated waveguide (SIW) antenna forms a back cavity to suppress the surface waves and separate the radiation aperture from the low-resistivity substrate. To increase the efficiency of OCA, a single-layer quartz superstrate is proposed. An analytical model to calculate the radiation efficiency is presented, and a detailed design approach is described. The proposed antenna is simulated using Ansoft HFSS. The simulated antenna has a maximum gain of 4.9 dBi and a radiation efficiency of 76.27%. The bandwidth of S11 below −10 dB is 44 GHz. The OCA has good performance and can be widely used in terahertz imaging and communication.

Axiomatic Design of Customised Additive Manufacturing Artefacts

Additive Manufacturing (AM) opens new horizons and paradigms for design, manufacturing and even tertiary activities. However, the quality of built parts in terms of mechanical properties, surface texture, geometrical and dimensional accuracy, remains highly dependent not only on AM systems’ parameters, but also on the chosen process among the numerous available AM processes. Therefore, to control the quality of built parts, it is essential to evaluate the influence of each process-related and system parameter. This can be done by building meta-models for the prediction of printed parts’ output properties or through experimentations using artefacts. Another approach consists in pure analytical modelling of AM processes and systems based on physics and thermo-mechanical phenomena occurring during the build phase. Finally, there are hybrid compensation models based on process physics analysis and experimentations using artefacts. In all of the aforementioned methods, AM artefacts are crucial to predict, build and validate models. However, essentially due to a lack of systematic design guidelines, several proposals for standardised AM artefacts ended up unsuccessfully. By taking advantage of concepts and tools of axiomatic design, this work introduces a detailed and systematic design approach for customised AM artefacts. A case study is also detailed and discussed.

Rule based intelligent system verbalizing mathematical notation

An adaptive and adaptable multi-purpose math-to-speech translation system is proposed in the paper. Along with the detailed presentation and design approach for the core math-to-speech translation system, exemplary output and tests are discussed. A scripting extension, providing flexibility of the system and enabling the user to adjust the output translations to his/hers preferences is incorporated into the presented solution. Some unit-tests and adaptable versions of translation rule sets are elaborated and evaluated by means of standard measures of machine translation quality. Designed as a flexible self contained solution, the presented system may be applied for various purposes such as e-learning audio presentation systems, educational tools for non-native speakers or visually impaired people, and may be easily adjusted to different national languages.

Dependability considerations of redundant sensor systems

Integrated sensor systems, which are produced in high volume for safety-critical applications such as automotive, require careful design and optimization strategies. To increase their reliability, such systems are often used in redundant configurations. However, this is in many cases not sufficient: requirements of high production yield, reliability in operation, low probabilities for non-detected system faults, in combination with fast development speed and low production costs require more detailed and careful design approaches. We consequently suggest statistical design, estimation and optimization approaches for efficient product definition and design. This methodology is summarized in a general way for redundant sensor systems. In a first step, the individual sensing channel performance is optimized statistically. In a second step, the dependability figures are optimized dependent on the redundant sensor output function and its diagnostic mechanism parameters based on statistical considerations of faults. The suggested methodology is shown exemplary for a redundant integrated linear Hall magnetic field sensor system for safety-critical automotive applications.

Environmental impact assessment of biomass process chains at early design stages using decision trees

Life cycle assessment (LCA) is generally considered as a suitable methodology for the evaluation of environmental impacts of processes. However, it requires large amount and often inaccessible process data at early design stages. The present study provides an approach to streamline LCA for a broad set of biomass process chains. The proposed method breaks away from conventional LCA work in that the purpose is to support decision at early stages assuming minimal use of data available and points to most dominant LCA impacts, providing useful feedback to process design. The prediction mechanism employs decision trees, which form “if-then rules” using a set of critical parameters of the process chain with respect to various environmental impacts. The models classify products into three classes, namely having low, medium, and high environmental impact. Data for model development were obtained from early design stages and include descriptors of the molecular structure of the product and process chain-related variables corresponding to chemistry, complexity, and generic process conditions. Twenty-three LCA metrics were selected as target attributes, according to the ReCiPe and the cumulative energy demand (CED) methods. A broad set of process chains is derived from the work of Karka et al. (Int J Life Cycle Assess 22(9):1418–1440, 2017). Results demonstrate that the average classification error for the decision trees ranges between 13.4 and 43.8% for the various LCA metrics and multifunctionality approaches. Allocation approaches present a better classification performance (up to 25% error) compared with the substitution approach for LCA metrics, such as climate change, CED, and human health. For the majority of models, low- and high-output classes are characterized by better predictive performance compared with the medium class. The interpretability of selected decision trees is analyzed in terms of pruning levels and “irrational” branches. The results of the application of the decision tress for recently published case studies show for instance that 8 out of 13 cases were correctly classified for CED. The proposed approach provides a first generation of models in the form of computationally inexpensive and easily interpretable decision trees that can be used as pre-screening tools for the environmental assessment of bio-based production ahead of detailed design and conventional LCA approaches. The transparent structure of the decision trees facilitates the identification of critical decision variables providing insights for improvement in terms of process parameters, biomass feedstock, or even targeted product.