Preliminary Design Calculations Research Articles

The Design and Optimization of Additively Manufactured Radial Compressor of a Miniature Gas Turbine Engine

Abstract This paper presents a multidisciplinary design methodology for a single-stage radial compressor of a small-scale gas turbine jet engine. The entire engine, producing more than 600N thrust with an engine diameter of less than 30 cm will be manufactured by the AM in a single piece. Therefore, it is crucial to pinpoint the design limitations that may arise due to the AM methods. The preliminary design calculations are carried out in the VKI's in-house Centrifugal Compressor Off-Design (CCOD) code. The detailed design and optimization studies coupled with CFD simulations are performed to improve the aerodynamic performance of the radial compressor by using the Sequential Quadratic Programming (SQP) method with an Adjoint solver in the VKI's in-house Computer Aided Design and Optimization (CADO) tool. In the final design, a large increase in thrust is obtained and the manufacturing constraints are satisfied.

Comparison of numerical and exact analyses in a neutron activation and decay chain

A method for solving a set of coupled linear first-order ordinary differential equations as it applies to neutron activation and subsequent radioisotope decay chains was developed that is easy to implement and accurate enough for most preliminary engineering design calculations. The method is applied to a specific radioisotope production scheme to evaluate the yield of the desired isotope as well as production of secondary and tertiary contaminant radioisotopes. An analytical closed-form solution was also derived for the same activation and decay chain to provide a basis for comparison; the analytical solution was benchmarked against several limiting cases to validate the equations. Results of the simulation involving the numerical approach were compared to the exact analytical solution. The numerical solution, while obviously not exact, is found to be close enough for engineering purposes. A discussion of the numerical precision of the result for the particular case are discussed.

The Design and Performance Prediction Model of an Integrated Scheme of a Membrane Bioreactor and Anaerobic Digester for the Treatment of Domestic Wastewater and Biowaste

An innovative and integrated scheme that encompasses two well-established waste treatment technologies, the aerobic biological degradation of organic matter bioprocess via membranes and anaerobic digestion, was demonstrated as a zero-waste approach that may effectively treat wastewater and biowaste in an integrated and symbiotic manner. Aiming to create a tool for the design, monitoring, and control of the scheme, prediction models were developed, validated, and implemented for the process simulation of the integrated scheme. The minimization of selected objective functions led to the estimation of the models’ parameters. The activated sludge model no. 1 (ASM1) was adopted for the simulation of the aerobic membrane bioreactor. The kinetic parameters were calibrated using volatile suspended solids and total nitrogen as the objective functions permitting the model to simulate the bioprocess satisfactorily (Nash–Sutcliffe efficiency > 0.86) and to calculate the concentration of the active biomass. The predominance of heterotrophic bacteria (4300 to 9770 mg COD/L) over autotrophic biomass (508 to 1422 mg COD/L) was showcased. For the anaerobic process unit, a simplified anaerobic digestion model 1 ADM1-R4 was used, and the first-order hydrolysis constants (kch 0.41 d−1, kpr 0.25 d−1, kli 0.09 d−1) and microbial decay rate (kdec 0.02 d−1) were evaluated, enabling an accurate prediction of biogas production rates. A full-scale implementation of the integrated scheme was conducted for a decentralized waste treatment plant in a small community. Preliminary design calculations were performed in order to estimate the values related to certain process and technical parameters. The performance of this full-scale plant was simulated by the developed model, presenting clear benefits for practical applications in waste treatment plants.

Towards preliminary design calculations with TRANSURANUS for application of Hastelloy cladding material

This study summarises the work performed to implementing the material properties for Hastelloy-N, of interest for GenIV MSRs, into the TRANSURANUS fuel performance code. The individual development of correlations on the basis of experimental data in the open literature, and the subsequent assessment with an independent dataset when available, also revealed the need for specific new experiments that have been pointed out. Following that, an integral assessment of the new code version was carried out as well. The simulation of a biaxial cladding burst tests from ORNL, with due consideration of the uncertainties and analysis by means of the new graphical output analysis tool TUPython for uncertainty and sensitivity analysis, provided encouraging results for the preliminary implementation of Hastelloy-N properties. The proposed set of material properties can therefore be readily implemented in any other fuel performance code.

Implementation of Three Phase Induction Motor Pre-Design Program on Electronic Circuit

In this study, the performance analysis of a 5.5 kW, 460 V, 60 Hz, 4-pole, and 3-phase squirrel- cage induction motor (IM) has been carried out by developing a portable electronic circuit, design, and the software, independent of any commercial software. The mathematical equations used in the design steps and the preliminary design of the main dimensions of the squirrel cage IM are realized with a developed electronic circuit. To perform preliminary design calculations Nextion 7-inch touch screen, Arduino mega 2560 microcontroller is used in electronic circuit design. Briefly, IM basic data are entered from the Nextion 7 inches touch screen in the electronic circuit created and the data are sent to the Arduino Mega 2560 microcontroller card via serial communication. On the Arduino Mega 2560 microcontroller board, IM mathematical calculations are accomplished, and the calculation results are presented on the Nextion screen. It has been observed that the analytical calculations and the calculation results in the developed calculation tool have been obtained in good agreement.

PERENCANAAN PEMBANGUNAN GEDUNG BARU 3 LANTAI “TABEK MAINAN” DI JALAN M.YAMIN KELURAHAN AUR KUNING KECAMATAN AUR BIRUGO TIGO BALEH KOTA BUKITTINGGI

The number of buildings that collapsed was caused by the ability of a structure that was not able to support the working load, causing significant loss of property and even life. Therefore, in planning the design of a building structure, it must be really full of accuracy, careful calculations and according to the requirements with reference to the Indonesian National Standard (Indonesian Loading Regulations for Buildings and Buildings SNI-2847-2019 and SNI-1726-2019). This study aims to plan the dimensions of structural elements, calculation of structural reinforcement. The structural element data used are the results of the preliminary design (Preliminary Design). The analysis is assisted by the SAP2000 Version 11 program with the selection of a network system structure system (Grid System). Based on the results of the Preliminary design calculation, data is obtained for the use of the superstructure of the 1st floor to the 3rd floor where the cross section of the main column is 40 x 50 cm, the terrace column is 30x30 cm, the main beam is 30x40 cm, and the joist is 20x30 cm. The planning of floor slabs and also not concrete which was carried out with Preliminary design was found to be 12 cm thick. Planning for the foundation using a well foundation with a depth of 2 meters, and using a concrete buis with a diameter of 1 meterKeywords: Preliminary design, SAP2000 analysis, reinforcement calculation, foundation bearing capacity

Fuzzy Unsteady-State Drainage Solution for Land Reclamation

Very well-drained lands could have a positive impact in various soil health indicators such as soil erosion and soil texture. A drainage system is responsible for properly aerated soil. Until today, in order to design a drainage system, a big challenge remained to find the subsurface drain spacing because many of the soil and hydraulic parameters present significant uncertainties. This fact also creates uncertainties to the overall physical problem solution, which, if not included in the preliminary design studies and calculations, could have bad consequences for the cultivated lands and soils. Finding the drain spacing requires the knowledge of the unsteady groundwater movement, which is described by the linear Boussinesq equation (Glover-Dumm equation). In this paper, the Adomian solution to the second order unsteady linear fuzzy partial differential one-dimensional Boussinesq equation is presented. The physical problem concerns unsteady drain spacing in a semi-infinite unconfined aquifer. The boundary conditions, with an initially horizontal water table, are considered fuzzy and the overall problem is translated to a system of crisp boundary value problems. Consequently, the crisp problem is solved using an Adomian decomposition method (ADM) and useful practical results are presented. In addition, by application of the possibility theory, the fuzzy results are translated into a crisp space, enabling the decision maker to make correct decisions about both the drain spacing and the future soil health management practices, with a reliable degree of confidence.

A Novel Semi-Analytical Approach to the Assessment of the Equivalent Stiffness of a Beam

Abstract This paper introduces several new approaches to stiffness calculation of the composite beam with a circular cross-section. The paper poses the problem of calculating the stiffness of the fibre-reinforced winded beam and introduces a new way of stiffness calculation. The novel semi-analytical calculation represents an approach that is less time consuming than conventional calculation methods or FEA methods. The expected application of the new method of calculation is in preliminary design and design calculations.

Sloshing Loads on the Head of an Annular Cylindrical Reactor Vessel

The head of a cylindrical reactor vessel must be designed for earthquake-induced sloshing force if there is insufficient freeboard. Herein, a design-oriented calculation method is developed for base-and head-supported annular tanks, where the annulus separates the reactor vessel and its core barrel. Charts are provided to enable preliminary design calculations. Examples are presented to describe the calculations.

Design and off-design system simulation of concentrated solar super-critical CO2 cycle integrating a radial turbine meanline model

The proper design of a Concentrated solar power (CSP) plant and the associated thermal energy storage requires a careful analysis of the yearly expected irradiance and environmental conditions. System simulations based on accurate components models allow the prediction of the performance of the plant and the analysis of the components interactions. The simulations of various scenarios provide information that will help tuning the design of the components to improve the performance of the whole system at design and off-design conditions. In this paper, the focus is set on the radial turbine expander which is one of the most important component. Classical system simulation approaches use map based performance model for the turbine. This require to generate the performance map either with meanline models, CFD simulations or experiments. This is not very convenient when iterating on the system design and if the actual turbine does not exist yet. In this work, a meanline model for radial inflow turbine operating with real gas has been implemented in MODELICA language for the first time to the authors’ best knowledge. This turbine model has been coupled with the available CSP sCO2 Brayton cycle model in MODELON ThermalPower library. A parametric study on a virtual test bench show the turbine performances for various rotational speed and inlet guide vane angle. The study focus then on the performance prediction of on and off design of the system with a 8 MW turbine obtained with a simple preliminary design calculation. The investigations showed that for the varying load conditions in the solar plant system, an improved operating point has been identified by adjusting the rotational speed and the inlet guide vane angle. Future work will focus on the use such system model with multi objective meta heuristic optimization.

PERENCANAAN ULANG PEMBANGUNAN MASJID WUSTHA PAYAKUMBUH

The mosque as a place of worship for Muslims, which is a building with a public function, must be designed in such a way for the comfort and safety of the building, both in terms of design and a strong and sturdy building structure. As a place of worship, especially prayer, which requires a large space with not many pillars (columns) in the middle of the room which is feared to break the prayer line. Therefore, accuracy is needed in the mosque construction process, especially the calculation of the loading of the building structure so that it is safe for the safety of users. This study aims to plan the dimensions of structural elements, calculation of structural reinforcement. The structural element data used are the results of the preliminary design (Preliminary Design). The analysis is assisted by the SAP2000 Version 11 program with the selection of a network system structure system (Grid System). Based on the results of the Preliminary design calculation, data is obtained for the use of the superstructure of the 1st floor to the 3rd floor where the cross section of the main column is 60x60 cm, the terrace column is 30x60 cm, the main beam is 40x60 cm, and the child beam is 30x50 cm. The planning of floor slabs and also not concrete which was carried out with Preliminary design was found to be 12 cm thick. Planning for the foundation using a well foundation with a depth of 4 meters, and by using a concrete buis with a diameter of 1 meter. Keywords:Preliminary design, SAP2000, Building Structure, Mosque,Foundation. 

Investigation of the operation of a ship’s synchronous generator based on a numerical model

The article presents the results of modeling a ship’s synchronous generator. Based on preliminary design calculations, a geometric model of the generator was built. The static and overclocking processes of the generator are investigated. For static modes, the frequency response of the process is obtained. A numerical model was used to identify a mechanical defect. On the example of a simulated defect of an electrical machine - the eccentricity of the generator rotor, the signature of the defect signal is obtained. The study revealed that the presence of rotor eccentricity leads to the appearance of a harmonic component in the spectrum of the force of large amplitude with a maximum value at a low frequency. Transient analysis was carried out using wavelet transformations. The results of the study of dynamics show how the rotor speed increases. The simulation revealed three frequency regions of the signal under study: the region of the increase in speed, the achievement of the critical speed (between the second and third seconds), and the exit to the steady-state. A diagram of a system for diagnosing defects in an electrical machine using a digital twin - a numerical model is proposed. Generator defects (mechanical and electromechanical) can be identified based on model data. Databases of defect signatures in a static mode and a diagnostic model, which contains algorithms for deciding on the presence of a defect, can serve as the basis of information for an operator to decide.

Preliminary Design for Segmental Joint of Precast Tunnel Liner

Abstract Responses of the segmental tunnel liner to external forces are primarily dependent on complicated interactions among construction process, soil structural interactions, segmental (longitudinal) joint characteristic etc. However, most proposed liner’s design procedures and recommendations are basically empirical and experience based, especially when the roles of tunnel joint are concerned. In the present study, a preliminary design calculation for the segmental joint with consideration of three practical conditions was proposed. The method adopts two main assumptions; the stiffness reduction factor and simplified pre-stressed concrete blocks, so that the flexural capacity of the segmental joint and its interactions to the main reinforced concrete segment body can be designated. Calculation examples are given for three most probable cases, namely, 1) the unbolted joint without joint opening, 2) the bolted joint without joint opening and 3) the unbolted segmental joint with allowing joint opening. Based on these calculations, the required compressive strength of concrete, thickness of liner, steel reinforcement, bolts and number of segments of the liner could be specified. The proposed method could well provide an engineer a tool to determine the initial joint configuration and its interaction to the overall tunnel lining.

Emissions prediction of an aero-piston gasoline engine during surveillance flight of an unmanned aerial vehicle

Purpose The purpose of this study is to perform the preliminary design, flight performance and exhaust emissions calculations of a piston engine powered unmanned aerial vehicle (UAV) during a flight cycle which consists of multiple flight altitudes and airspeeds. Design/methodology/approach A genuine computer model in Matlab/Simulink was developed to predict the size and weight of UAV and piston engine (using Avgas 100LL fuel) performance together with exhaust emissions in an iterative process. Findings The amount of emitted exhaust gases including carbon dioxide, carbon monoxide, hydrocarbons and nitrogen oxides were calculated in a typical UAV mission profile as a whole and also divided into mission flight segments. Research limitations/implications Emissions were calculated based on fuel flow and engine speed inputs based on ground test data for emission indices. Test data for emission indices was very limited. Practical implications As UAV utilization has been increasing around the world, this study presents important and noticeable results on the emissions that need to be considered for environmental purposes. Originality/value In literature, emission prediction studies for UAVs are very rare. In fact, UAVs typically have quite different flight speeds and altitudes than regular manned aircraft and emissions change with speed and altitude. Additionally, unlike manned aircraft, UAVs can fly more than 24 h with different operation characteristics. The originality of this study presents the emission predictions of a piston engine UAV which flies with a significantly different mission profile than a manned aircraft.

Design and performance evaluation of series hybrid electric vehicle using backward model

Hybrid electric vehicles (HEVs) are becoming a more promising means of transportation mainly because of environmental issues and depletion of fossil fuel resources. This study deals with the basic theoretical knowledge for describing their behaviour in acceleration, cruising, deceleration and control strategies. Preliminary design calculations for a series HEV bus are carried out in MATLAB environment using a backward model. In addition to this, the rule-based algorithm is implemented to compare fuel consumption, battery's state of charge (SOC) and energy-saving possibilities. The model is firstly tested for highway and city drive cycles for SOC limits of 0.6 and 0.7. Further, prolonged simulations are conducted for both the highway and city drive cycles for four different SOC limits and three parameters of the hybrid vehicle (SOC of battery, fuel power and average charging power) are observed and compared with each other. The performance indexes of both drive cycles are estimated and it is found that higher performance indexes are obtained using power-split mode and greater SOC lower limit as internal combustion engine is more efficient when operated in this mode.

Influence of Mass Parameters Modification on Manoeuvrability of 9K33 „OSA” Set 9M33M3 Missile

This paper discusses analytical method for realization of preliminary missile stability design calculations. Action has been taken to estimate influence of replacing massive blocks of analogue electronics with compact solutions of digital electronics in missiles remaining in operation. On an example of a short-range 9M33M3 missile from 9K33 „OSA” set and its previously analysed aerodynamic characteristics, the analysis of the centre of gravity location impact was carried out to determine maximum loads occurring in the two most interesting phases of flight: after booster engine burnout and directly after cruise engine burnout. The suggestion for modification suggestion of flight parameters’ optimization is presented which defines stability and its critical impact of these parameters on aeronautical engineering. For the tested missile, the methodology suggestions for the modification is discussed with the comparison of serially produced copies to define the ability of improving the flight parameters. The paper includes visualizations and quantity analysis of: maximal loads on the fuselage, minimal turn radius, and control wing inclination angle as missile’s angle of attack function.

Обґрунтування рішень технічного переоснащення котлоагрегату Трипільської теплоелектростанції

Здійснено аналіз варіантів, зокрема з урахуванням досвіду технічного переоснащення енергоблоку ст. № 4, виконано передпроектні розрахунки технологічних схем для системи приготування пилу, подачі пилу в котел та спалювання в котлі ТПП-210А блоку ст. № 3 Трипільської ТЕС вугілля марок Г та ДГ з максимальним збереженням компоновки наявного обладнання за різних навантажень, пусків і зупинів, оцінено досяжний діапазон потужності блоку під час роботи на вугіллі марок Г та ДГ та обґрунтовано сукупність технічних рішень для переведення котла ст. № 3 на газове вугілля. Виконано позонний тепловий розрахунок топки за визначеними варіантами за різних навантажень. Проведено розрахункову оцінку діапазону навантаження для забезпечення умов РШВ, запобігання шлакуванню ширм та збереження наявних температурних умов експлуатації стінок НРЧ під час спалювання газового вугілля різної якості. Виконано повіркові теплові розрахунки котла ТПП-210А ст. № 3 згідно з Нормативним методом з використанням довідкових даних для визначення можливості несення котлом номінального та часткових навантажень. Загалом було виконано 9 варіантів розрахунків (на антрациті з калорійністю 5500 ккал/кг на номінальному навантаженні – для верифікації застосованого методу та вихідних даних щодо котла; на двох розрахункових паливах на навантаженнях 100, 90, 80 та 70 % від номінального). Для розрахунку використовували фактичні значення присмоктів у топку, елементи конвективної шахти та РПП. Підтверджено можливість та доцільність реалізації схеми зі скиданням відпрацьованого сушильного агенту до скидних пальників як витратно-швидкісними розрахунками пилосистем і пальників, так і повірковими позонними розрахунками топки для обох видів розрахункового вугілля на навантаженнях від 100 до 70 % від номінального. Показано, що температура газів та питоме теплове навантаження променесприймальної поверхні у всіх зонах топки під час спалювання газового вугілля не перевищують ті, що реалізуються під час спалювання антрациту, що свідчить про непогіршення наявних (як під час спалювання антрациту) температурних умов експлуатації стінок НРЧ під час спалювання газового вугілля у всіх зонах топки.

Finding an optimal blade-profile to improving the performance of partially admitted turbines

Purpose This paper aims to present the designing and investigating various types of impulse blade profiles to find the optimal profile that has better performance than the first or original blade. The studied model is a turbine with an output power below 1 MW and a large pressure ratio up to 20, which is used to gain relatively high specific work output. As a result of its low mass flow rate, the turbine is used under partial-admission conditions. The turbine’s stator is a group of convergence–divergence nozzles that provide supersonic flow. Design/methodology/approach More than 10 types of two-dimensional blade profiles were designed using the developed preliminary design calculations and numerical analysis. The numerical results are validated using the existing experimental results. Finally, the case with improved performance is introduced as the final optimum case. Findings It was found that the performance parameters such as efficiency, power and torque are increased by more than 8% in the selected best model, in comparison with the original model. Moreover, the total pressure loss is 12% decreased for the selected model. Finally, the selected profile with superior performance is proposed. Originality/value Simultaneous numerical tests are conducted to examine the interaction of different supersonic blade profiles with the partially injected flow to the rotor.

Integrated design optimization of spar floating wind turbines

A linearized aero-hydro-servo-elastic floating wind turbine model is presented and used to perform integrated design optimization of the platform, tower, mooring system, and blade-pitch controller for a 10 MW spar floating wind turbine. Optimal design solutions are found using gradient-based optimization with analytic derivatives, considering both fatigue and extreme response constraints, where the objective function is a weighted combination of system cost and power quality. Optimization results show that local minima exist both in the soft-stiff and stiff-stiff range for the first tower bending mode and that a stiff-stiff tower design is needed to reach a solution that satisfies the fatigue constraints. The optimized platform has a relatively small diameter in the wave zone to limit the wave loads on the structure and an hourglass shape far below the waterline. The shape increases the restoring moment and natural frequency in pitch, which leads to improved behaviour in the low-frequency range. The importance of integrated optimization is shown in the solutions for the tower and blade-pitch control system, which are clearly affected by the simultaneous design of the platform. State-of-the-art nonlinear time-domain analyses show that the linearized model is conservative in general, but reasonably accurate in capturing trends, suggesting that the presented methodology is suitable for preliminary integrated design calculations.

Методика інженерних розрахунків параметрів обладнання для зневоднення твердих побутових відходів у сміттєвозі

A mathematical model of the operation of the solid domestic waste dewatering drive in a garbage truck is proposed. This model allows us to study the dynamics of this process and obtain regression equations for determining the nominal value of the angular velocity of the hydraulic motor. During the study there has been used the numerical method of Runge–Kutta–Vellberg of the fourth order with a variable step of integration, and regression results of one-factor experiments and other pair of dependencies with a selection of the best function of the 16 most common variants on the criterion of the maximum correlation coefficient. An analytical study of a simplified mathematical model of the operation of the solid domestic waste dewatering system in a garbage truck by solving a system of ordinary linear differential equations using Laplace transformations and by decomposing the expression into simple fractions allowed us to obtain analytical interdependencies of its main parameters, which can be used to perform preliminary design calculations of the parameters of this drive. When comparing the results obtained using full and simplified mathematical models for dewatering solid domestic waste in a garbage truck, in particular the angular velocity of the hydraulic motor, the error was 7,06 %, which is acceptable for performing preliminary design calculations of the main drive parameters. A scientifically-based method of design calculation of the drive for dewatering solid domestic waste in a garbage truck is proposed. This method allows to obtain the basic geometric, power and speed parameters and is one of the components for solving the problem of creating scientific and technical bases for designing highly efficient working bodies of machines for cleaning and primary processing of solid domestic waste. The main geometric, power and speed parameters of the drive for dewatering solid domestic waste in a garbage truck are obtained.