A preliminary multidisciplinary design procedure for tactical missiles

2018 ◽  
Vol 233 (9) ◽  
pp. 3445-3458 ◽  
Author(s):  
Mostafa Khalil ◽  
Anwer Hashish ◽  
Hamed M Abdalla
Keyword(s):  
System Development ◽  
Slenderness Ratio ◽  
Design Procedure ◽  
The Body ◽  
Multidisciplinary Design ◽  
Design Parameters ◽  
Preliminary Design ◽  
Empirical Formulas ◽  
Detail Design ◽  
The Impact

During missile system development, multidisciplinary design procedure is iteratively implemented based on the missile objective and target nature including internal ballistic, warhead function, and airframe configuration. By applying missile preliminary design, a good estimation for different design parameters can be obtained which will be useful through further detail design process. The aim of this paper is to build a preliminary design procedure for an unguided tactical missile that uses single-stage solid propellant motor to deliver a defined payload mass to a desired ground range. Based on data of available similar mature missile systems, two empirical formulas are developed to serve in the initial sizing of the missile with consideration of slenderness ratio, warhead mass, and desired ground range. Two different design concepts are implemented for tubular and star grains with different propellant compositions and chamber filling coefficients while the body-alone airframe configuration is adopted. The results demonstrate the capability of the proposed design procedure in defining the detailed design parameters. The impact of changing the propellant compositions and chamber filling coefficients on the obtained ground range is also explored.

Making Up 3D Bodies

2021 ◽  
Vol 4 (2) ◽  
pp. 1-9
Author(s):  
Kiona Hagen Niehaus ◽  
Rebecca Fiebrink
Keyword(s):  
Software Tool ◽  
The Body ◽  
Design Parameters ◽  
Artistic Practice ◽  
Human Form ◽  
Modeling Systems ◽  
Exploratory Approach ◽  
Disability Status ◽  
High Level ◽  
The Impact

This paper describes the process of developing a software tool for digital artistic exploration of 3D human figures. Previously available software for modeling mesh-based 3D human figures restricts user output based on normative assumptions about the form that a body might take, particularly in terms of gender, race, and disability status, which are reinforced by ubiquitous use of range-limited sliders mapped to singular high-level design parameters. CreatorCustom, the software prototype created during this research, is designed to foreground an exploratory approach to modeling 3D human bodies, treating the digital body as a sculptural landscape rather than a presupposed form for rote technical representation. Building on prior research into serendipity in Human-Computer Interaction and 3D modeling systems for users at various levels of proficiency, among other areas, this research comprises two qualitative studies and investigation of the impact on the first author's artistic practice. Study 1 uses interviews and practice sessions to explore the practices of six queer artists working with the body and the language, materials, and actions they use in their practice; these then informed the design of the software tool. Study 2 investigates the usability, creativity support, and bodily implications of the software when used by thirteen artists in a workshop. These studies reveal the importance of exploration and unexpectedness in artistic practice, and a desire for experimental digital approaches to the human form.

Preliminary Design of Small-Scale Supercritical CO2 Radial Inflow Turbines

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Tina Unglaube ◽  
Hsiao-Wei D. Chiang
Keyword(s):  
Optimum Design ◽  
Supercritical Co2 ◽  
Velocity Ratio ◽  
Design Procedure ◽  
Expansion Ratio ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Small Scale ◽  
Preliminary Design ◽  
Line Design

Abstract In recent years, supercritical CO2 (sCO2) Brayton cycles have drawn the attention of researchers due to their high cycle efficiencies, compact turbomachinery, and environmental friendliness. For small-scale cycles, radial inflow turbines (RIT) are the prevailing choice and one of the key components. A mean line design procedure for sCO2 RIT is developed and design space exploration conducted for a 100 kW-class turbine for a low-temperature waste-heat utilization sCO2 Brayton cycle. By varying the two design parameters, specific speed and velocity ratio, different turbine configurations are setup and compared numerically by means of computational fluid dynamics (CFD) simulations. Results are analyzed to conclude on optimum design parameters with regard to turbine efficiency and expansion ratio. Specific speeds between 0.2 and 0.5 are recommended for sCO2 RIT with small though flow (3 kg/s). The higher the velocity ratio, the bigger the turbine expansion ratio. Pairs of optimum design parameters that effectuate maximum efficiency are identified, with smaller velocity ratios prevailing for smaller specific speeds. The turbine simulation results for sCO2 are compared to well-established recommendations for the design of RIT from literature, such as the Balje diagram. It is concluded that for the design of sCO2 RITs, the same principles can be used as for those for air turbines. By achieving total-to-static stage and rotor efficiencies of 84% and 86%, respectively, the developed mean line design procedure has proven to be an effective and easily applicable tool for the preliminary design of small-scale sCO2 RIT.

scholarly journals Preliminary Sub-Systems Design Integrated in a Multidisciplinary Design Optimization Framework

2017 ◽  
Vol 2017 (4) ◽  
pp. 9-23
Author(s):  
Marco Fioriti ◽  
Luca Boggero ◽  
Sabrina Corpino
Keyword(s):  
Design Optimization ◽  
Multidisciplinary Design Optimization ◽  
Systems Design ◽  
Aircraft Design ◽  
Multidisciplinary Design ◽  
Design Parameters ◽  
Preliminary Design ◽  
Horizon 2020 ◽  
Optimization Framework ◽  
Complex Subject

Abstract The aircraft design is a complex subject since several and completely different design disciplines are involved in the project. Many efforts are made to harmonize and optimize the design trying to combine all disciplines together at the same level of detail. Within the ongoing AGILE (Horizon 2020) research, an aircraft MDO (Multidisciplinary Design Optimization) process is setting up connecting several design tools and competences together. Each tool covers a different design discipline such as aerodynamics, structure, propulsion and systems. This paper focuses on the integration of the sub-system design discipline with the others in order to obtain a complete and optimized aircraft preliminary design. All design parameters used to integrate the sub-system branch with the others are discussed as for their redefinition within the different detail level of the design.

scholarly journals Design of impact dampers for transporting cargoes by two-link vehicles

2021 ◽  
Vol 2 (7 (110)) ◽  
pp. 85-94
Author(s):  
Ihor Vikovych ◽  
Ljubomyr Krainyk ◽  
Roman Zinko ◽  
Vitalij Popovych ◽  
Orest Horbai
Keyword(s):  
Rational Design ◽  
The Body ◽  
Design Parameters ◽  
Viscoelastic Damping ◽  
Impact Loads ◽  
Vibration Protection ◽  
Rational Design Parameters ◽  
Transition Modes ◽  
Impact Phenomena ◽  
The Impact

This paper considers the influence of the transitional modes of movement (acceleration, braking) of a multi-link vehicle on the vibration protection of transported non-fixed or partially fixed cargoes. The impact phenomenon, in this case, can be strengthened by the existence of coupling mechanisms between the links of a multi-link vehicle. To reduce such horizontal impact loads, it is advisable to use elements with viscoelastic damping in the coupling devices of a multi-link vehicle. To study the actual impact phenomena during the transportation of non-fixed or partially fixed cargoes under the extreme modes of movement of two-link vehicles, it is proposed to use a flat two- and three-mass dynamic model with viscoelastic damping. At the same time, the theory of elastic impact has been applied while the elastic-damping characteristics of vehicles' suspensions were not taken into consideration. It has been shown that the reported research results make it possible to estimate the approximate values of the mechanical parameters for restrictive devices that protect non-fixed or partially fixed cargoes from impact, during the transition modes of transportation, depending on the conditions of motion. This practically makes it possible to select the rational design parameters for the elements of viscoelastic restrictive devices, in particular elastic elements and dampers, in order to reduce impact loads on non-fixed heavy cargoes during transportation under extreme modes of movement. Based on this study, a procedure of vibration protection of non-fixed or partially fixed cargoes in the body of a two-link vehicle during its uneven movement has been proposed, which implies determining the maximum dynamic loads on these cargoes as well as the possibility of choosing the rational design parameters for restrictive devices in order to prevent or reduce the impact of these cargoes hitting the restrictive devices

scholarly journals Closed-Form Formulas for Automated Design of SiC-Based Phase-Shifted Full Bridge Converters in Charger Applications

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5380
Author(s):  
Kornel Wolski ◽  
Piotr Grzejszczak ◽  
Marek Szymczak ◽  
Roman Barlik
Keyword(s):  
High Voltage ◽  
High Power ◽  
Output Voltage ◽  
Design Procedure ◽  
Automated Design ◽  
Design Parameters ◽  
Switching Frequency ◽  
Voltage Level ◽  
Voltage Output ◽  
The Impact

Phase-Shifted Full Bridge (PSFB) topology in its four-diode variant is the choice with the lowest part count in applications that demand high power, high voltage, and galvanic isolation, such as in Electric Vehicle (EV) chargers. Even though the topology is prevalent in power electronics applications, no single, unified analytical model has been proposed for the design process of four-diode PSFB converters. As a result, engineers must rely on simulations and empirical results obtained from previously built converters when selecting components to properly match the DC source voltage level with the DC load voltage requirements. In this work, the authors provide a design-oriented analysis approach for obtaining the output voltage and semiconductor current values, ready for implementation in a spreadsheet- or MATLAB-type software to automate design optimization. The proposed formulas account for all the first-order nonlinear dependencies by considering the impact of each of the following eight design parameters: DC-link voltage, load resistance, phase-shift ratio, switching frequency, transformer turns ratio, magnetizing inductance, series inductance, and output inductance. The results are verified through experiments at the power level of 10 kW and the DC-link voltage level of 800 V by using a grid simulator and a SiC-based two-level Active Front End (AFE) with a DC–DC stage based on the PSFB topology. The accuracy of the output voltage formula is determined to be around 99.6% in experiments and 100.0% in simulations. Based on this exact model, an automated design procedure for high-power high-voltage SiC-based PSFB converters is developed. By providing the desired DC-link voltage, output voltage, output power, output current ripple factor, maximum temperatures, and semiconductor and heatsink databases, the algorithm calculates a set of feasible designs and points to the one with the lowest semiconductor losses, dimensions, or cost.

Preliminary Design Assessments of Pusher Geared Counter-Rotating Open Rotors: Part II — Impact of Low Pressure System Design on Mission Fuel Burn, Certification Noise and Emissions

2015 ◽  
Author(s):  
Pablo Bellocq ◽  
Inaki Garmendia ◽  
Vishal Sethi
Keyword(s):  
System Design ◽  
Rotational Speed ◽  
Low Pressure ◽  
Design Parameters ◽  
Preliminary Design ◽  
Pressure System ◽  
Regulatory Constraints ◽  
Fuel Burn ◽  
Low Pressure System ◽  
The Impact

In this 2-part publication, the impact of the main low pressure system parameters of a counter rotating Geared Open Rotor (GOR) on mission fuel burn, certification noise and emissions is presented for a 160 PAX medium haul class aircraft. Due to their high propulsive efficiency, GORs have the potential to significantly reduce fuel consumption and emissions relative to conventional high bypass ratio turbofans. However, this novel engine architecture presents many design and operational challenges both at engine and aircraft level. The assessment of the impact of the main low pressure preliminary design parameters of GORs on mission fuel burn, certification noise and emissions is necessary at preliminary design stages in order to identify optimum design regions. These assessments may also aid the development process when compromises need to be performed as a consequence of design, operational or regulatory constraints. Part I of this two-part publication describes the main low pressure (LP) system design choices for a GOR as well as the preliminary design philosophy and simulation framework developed for the assessments. Part II presents the assessment studies. A fixed reference aircraft and mission were used to evaluate the different GOR engine designs. The results are presented in the form of 1-D or 2-D plots in which one or two design parameters are varied at the same time. The changes in mission fuel burn, certification noise and emissions are expressed as differences relative to a baseline design, due to the fact that preliminary design tools were used for the assessments. The main conclusions of the study are: • Increasing spacing between the propellers (from 0.65 to 1.3m) reduces noise significantly (∼6 EPNdB for each certification point) with a relatively small fuel burn penalty (∼0.3–0.5%) • Relative to unclipped designs, 20% clipped CRPs reduce flyover noise by at least 2.5 EPNdB and approach noise by at least 4.5 EPNdB. The corresponding fuel burn penalty is ∼2%. • Sideline and flyover noise can be reduced by increasing the diameter of the CRP and appropriately controlling CRP rotational speeds. Approach noise can be reduced by either reducing the diameters or the rotational speeds of the propellers. • Regardless of clipping, reducing the rotational speed of the rear propeller relative to the forward propeller reduces noise and, to a certain limit, also mission fuel burn. Further reductions in rotational speed would have an adverse effect on fuel burn. • For given rotational speeds of the propellers, the torque ratio of the gearbox is fixed within ±3%.

Adaptive Preliminary-Design Workflow for Aero Engine Secondary Air System Cavities With an Application Case of Windage and Heat Transfer in a Rotor-Stator Cavity With Axial Through Flow

2018 ◽  
Author(s):  
Toni Wildow ◽  
Hubert Dengg ◽  
Klaus Höschler ◽  
Jonathan Sommerfeld
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Geometry Model ◽  
Through Flow ◽  
Air System ◽  
Secondary Air ◽  
The Impact

At the preliminary design stage of the engine design process, the behaviour and efficiency of different engine designs are investigated and evaluated in order to find a best matching design for a set of engine objectives and requirements. The prediction of critical part temperatures as well as the reduction of the uncertainty of these predictions is decisive to bid a competitive technology in aerospace technology. Automated workflows and Design of Experiments (DOE) are widely used to investigate large number of designs and to find an optimized solution. Nowadays, technological progress in computational power as well as new strategies for data handling and management enables the implementation of large DOEs and multi-objective optimizations in less time, which also allows the consideration of more detailed investigations in early design stages. This paper describes an approach for a preliminary-design workflow that implements adaptive modelling and evaluation methods for cavities in the secondary air system (SAS). The starting point for the workflow is a parametric geometry model defining the rotating and static components. The flow network within the SAS is automatically recognized and CFD and Thermal-FE models are automatically generated using a library of generic models. Adaptive evaluation algorithms are developed and used to predict values for structural, air system and thermal behaviour. Furthermore, these models and evaluation techniques can be implemented in a DOE to investigate the impact of design parameters on the predicted values. The findings from the automated studies can be used to enhance the boundary conditions of actual design models in later design stages. A design investigation on a rotor-stator cavity with axial through flow has been undertaken using the proposed workflow to extract windage, flow field and heat transfer information from adiabatic CFD calculations for use in thermal modelling. A DOE has been set up to conduct a sensitivity analysis of the flow field properties and to identify the impact of the design parameters. Additionally, impacts on the distribution of the flow field parameters along the rotating surface are recognized, which offers a better prediction for local effects in the thermal FE model.

scholarly journals Preliminary Gas Turbine Combustor Design Using a Genetic Algorithm

1997 ◽  
Author(s):  
Arnaud Despierre ◽  
Peter J. Stuttaford ◽  
Philip A. Rubini
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Gas Turbine ◽  
Combustion Process ◽  
Design Procedure ◽  
Design Tool ◽  
Performance Criteria ◽  
Design Parameters ◽  
Transfer Model ◽  
Preliminary Design

A genetic algorithm, coupled with a versatile preliminary design tool, is employed to demonstrate the concept of an autonomous design procedure for gas turbine combustors with user specified performance criteria. The chosen preliminary design program utilises a network based approach which provides considerable geometric flexibility allowing for a wide variety of combustor types to be represented. The physical combustor is represented by a number of independent, though interconnected, semi-empirical sub-flows or elements. A full conjugate heat transfer model allows for convection, conduction and radiative heat transfer to be modelled and a constrained equilibrium calculation simulates the combustion process. The genetic algorithm, whose main advantage lies in its robustness, uses the network solver in order to progress towards the optimum design parameters defined by the user. The capabilities of the genetic program are demonstrated for some simple design requirements, for example zone fuel/air ratio, pressure drop and wall temperatures.

Preliminary Design Assessments of Pusher Geared Counter-Rotating Open Rotors: Part I — Low Pressure System Design Choices, Engine Preliminary Design Philosophy and Modelling Methodology

2015 ◽  
Author(s):  
Pablo Bellocq ◽  
Iñaki Garmendia ◽  
Vishal Sethi
Keyword(s):  
System Design ◽  
Low Pressure ◽  
Design Parameters ◽  
Preliminary Design ◽  
Simulation Framework ◽  
Pressure System ◽  
Design Philosophy ◽  
Fuel Burn ◽  
Low Pressure System ◽  
The Impact

In this 2-part publication, the impact of the main low pressure system parameters of a pusher counter rotating Geared Open Rotor (GOR) on mission fuel burn, certification noise and emissions is presented for a 160 PAX medium haul class aircraft. Due to their high propulsive efficiency, GORs have the potential to significantly reduce fuel consumption and emissions relative to conventional high bypass ratio turbofans. However, this novel engine architecture presents many design and operational challenges both at engine and aircraft level. The assessment of the impact of the main low pressure preliminary design parameters of GORs on mission fuel burn, certification noise and emissions is necessary at preliminary design stages in order to identify optimum design regions. These assessments may also aid the development process when compromises need to be performed as a consequence of design, operational or regulatory constraints. Part I of this two-part publication describes the main low pressure (LP) system design choices for a GOR as well as the preliminary design philosophy and simulation framework developed for the assessments. Part II presents the assessment studies. The simulation framework described in this paper comprises the following models: engine and aircraft performance, engine mechanical design and weight, engine certification noise and emissions. A novel aspect of the presented simulation framework is that the design point efficiency and the design feasibility of the low pressure components are calculated for each engine design.

Design Optimization of a Prismatic-Revolute-Revolute Joint Hand for Grasping From Unconstrained Vehicles

2017 ◽  
Author(s):  
Spencer B. Backus ◽  
Aaron M. Dollar
Keyword(s):  
Parametric Model ◽  
The Body ◽  
Design Parameters ◽  
Small Space ◽  
Revolute Joint ◽  
Wide Range ◽  
Grasping And Manipulation ◽  
Interaction Task ◽  
The Impact ◽  
Or Task

Adding grasping and manipulation capabilities to unconstrained vehicles such as UAVs, AUVs, and small space craft so that they can deliver cargo, grasp and retrieve objects, perch on features in the environment, and even manipulating their environment is an ongoing area of research. However, these efforts have relied heavily on structuring the interaction task and have predominantly utilized existing gripper designs that were not specialized for the platform or task. In this paper, we present a parametric model of a novel underactuated hand design that is composed of prismatic-revolute-revolute joint fingers. This kinematic configuration attempts to minimize disturbance forces to the body of the vehicle while achieving stable grasps on a wide range of objects under significant positional uncertainty. In particular, this paper investigates the impact of various design parameters, including the relative link lengths and force allocation across the three joints, on grasping performance and suggests optimal design parameters for a prototype hand.

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