Development of a Scaled Vehicle Model for Dynamics Testing

2021 ◽  
Author(s):  
R.R. Hewavithana ◽  
◽  
J.P.L. Ravihara ◽  
K.K.S. Wishwajith ◽  
U.L.S. Perera ◽  
...  
Keyword(s):  
Computer Simulations ◽  
Simulation Models ◽  
Autonomous Driving ◽  
Aggressive Driving ◽  
Scaled Model ◽  
State Behaviour ◽  
Dynamic Similitude ◽  
Scaled Models ◽  
Vehicle Testing ◽  
Future Work

The interest in using scaled models for dynamics testing of prototype vehicles is growing due to the high demand for autonomous driving. In the early design phases, vehicle testing is done using computer simulations. Even though computer simulations are proven to be extremely helpful in designing prototypes, simulation models need to be validated using realworld testing. There are high costs involved in vehicle testing and it’s dangerous to conduct aggressive driving manoeuvres with real drivers. As a solution, researchers have used scaled models. To validate the computer simulations, researchers matched the scaled model test data with full-size vehicle prototypes considering the dynamic similitude. However, previous work was limited to the analysis of the steady-state behaviour of vehicles. To accurately predict the behaviour, the transientstate response must be tested as well. Therefore, this paper outlines the precursory work of a scaled model with the ability to test both states during vehicle manoeuvres. This paper is structured as follows. Section II presents related work. Section III elaborates on the mathematical modelling and present the results of the computer simulations. Section IV presents the scaled model which will be developed. Section V concludes the findings, and present the future work of research.

scholarly journals The concept and methodical assumptions for the development of dynamically scaled aircraft model (passenger aircraft)

2019 ◽  
Vol 304 ◽  
pp. 02010
Author(s):  
Aleksander Olejnik ◽  
Stanisław Kachel ◽  
Robert Rogólski ◽  
Jarosław Milczarczyk
Keyword(s):  
Structural Properties ◽  
Computer Simulations ◽  
Complete Information ◽  
Scaled Model ◽  
Scale Factors ◽  
University Of Technology ◽  
Numerous Data ◽  
Passenger Aircraft ◽  
Scaled Models ◽  
The Military

The article describes the concept of scaled model and its application in the process of real aircraft prototyping. Computer simulations of aerodynamic flows are commonly used in the design of aircraft. Numerous data on the characteristics of an airplane can be obtained using tunnel tests of geometry scaled models. To get complete information in extreme or unstable conditions, dynamically scaled models are tested. The scaled model is reduced model of the real airplane which has specific qualities similar to real aircraft qualities and these relations are strictly defined with characteristic similarity numbers (factors). The paper presents methodology for determining scale factors in relation to geometric, aerodynamic and structural properties (mass, stiffness) of the aircraft. The methodology was presented on the example of passenger aircraft (Tu-154M) model developed in Faculty of Mechatronics and Aerospace of the Military University of Technology (FMA MUT Warsaw, PL).

scholarly journals Hydraulic physical model production with Computer Numerically Controlled (CNC) manufacturing techniques

2018 ◽  
Vol 40 ◽  
pp. 05065 ◽  
Author(s):  
Pierre-Yves Henry ◽  
Jochen Aberle ◽  
Christy Ushanth Navaratnam ◽  
Nils Ruther
Keyword(s):  
Surface Roughness ◽  
Physical Models ◽  
Roughness Effects ◽  
Scaled Model ◽  
Construction Methods ◽  
Roughness Elements ◽  
Computer Numerically Controlled ◽  
Complex Boundary ◽  
Manufacturing Techniques ◽  
Scaled Models

Physical models are a well-accepted tool in hydraulic engineering, allowing for the detailed characterisation of flow processes and the validation of structure designs with complex boundary conditions. The methods used to construct physical models typically produce a surface roughness which does not necessarily scale with the surface roughness of the prototype. In this context, this paper discusses novel construction methods allowing a detailed reproduction of roughness elements in scaled models, such as Computer Numerically Controlled (CNC) manufacturing techniques and bed casting techniques. In particular, the present paper details the protocols developed to mill out a correct representation of the complex rock-fractured geometry of a closed channel which was obtained from Terrestrial Laser Scanners. The novelty of this scaled model production is the implementation of optical accesses in a closed (pressurized) hydraulic model, to allow for Particle Image Velocimetry measurements with a minimum impact on the reproduced roughness elements. The effectiveness of this production protocol is discussed in the context of modelling the roughness effects on the flow regime.

Review of current research trends in bird strike and hail impact simulations on wing leading edge

2018 ◽  
Vol 90 (4) ◽  
pp. 602-612 ◽  
Author(s):  
Zdobyslaw Jan Goraj ◽  
Kamila Kustron
Keyword(s):  
Computer Simulations ◽  
Leading Edge ◽  
Simulation Models ◽  
Bird Strike ◽  
Physical Test ◽  
Content Type ◽  
Physical Tests ◽  
Statistical Approaches ◽  
The Impact ◽  
Hail Impact

Purpose Bird strike and hail impact resistances are considered in relation to the fulfilment of airworthiness/crashworthiness regulations as specified by appropriate aviation authorities. Before aircraft are allowed to go into service, these regulations must be fulfilled. This includes the adaption of the wing leading edge (LE) structure to smart diagnostics and an easy repair. This paper aims to focus on the wing LE, although all forward-facing aircraft components are exposed to the impact of foreign object during the flight. The best practices based on credible simulations which may be appropriate means of establishing compliance with European Aviation safety Agency and Federal Aviation Administration regulations regarding bird strikes, together with the problem of collisions with hailstones, are overviewed in aspect of accuracy and computing cost. Design/methodology/approach The best means of evaluating worldwide certification standards so as to be more efficient for all stakeholders by reducing risk and costs (time and money consuming) of certification process are recommended. The very expensive physical tests may be replaced by adequate and credible computer simulations. The adequate credible simulation must be verified and validated. The statistical approaches for modelling the uncertainty are presented in aspect of computing cost. Findings The simulation models have simplifications and assumptions that generate an uncertainty. The uncertainty must be identified in benchmarking tests. Instead of using “in house” physical tests, there are scientific papers available in open literature thanks to the new trend in worldwide publication of the research results. These large databases can be efficiently transform into useful benchmark thanks to data mining and knowledge discovery methods and big data analyses. The physical test data are obtained from tests on the ground-based demonstrator by using high-speed cameras and a structural health monitoring system, and therefore, they should be applied at an early stage of the design process. Originality/value The sources of uncertainty in simulation models are expressed, and the way to their assessment is presented based on statistical approaches. A brief review of the current research shows that it widely uses efficient numerical analysis and computer simulations and is based on finite element methods, mesh structure as well as mesh free particle models. These methods and models are useful to analyse airworthiness requirements for damage tolerance regarding bird-strike and hail impact and haves been subjected to critical review in this paper. Many original papers were considered in this analysis, and some of them have been critically reviewed and commented upon.

scholarly journals Modeling the propagation of the Dengue, Zika and Chikungunya virus in the city of Bello using Agent-Based Modeling and Simulation

2021 ◽  
Author(s):  
Rafael Mateus Carrion ◽  
Susana Alvarez Zuluaga ◽  
Mariajose Franco Orozco ◽  
Paula Alejandra Escudero Marín
Keyword(s):  
Computational Cost ◽  
Simulation Models ◽  
Transmission Dynamics ◽  
Agent Based ◽  
Vector Borne Diseases ◽  
Ode Models ◽  
Vector Borne ◽  
Future Work ◽  
The City ◽  
High Computational Cost

Agent-Based Models (ABM) have become a very useful tool to simulate the propagation of infectious diseases. To enhance the scope of these simulation models, some authors have combined ABMs with ODE models which are called Hybrid ABMs, and allows the simulation of models that demand a very high computational cost. In the present project, the main approach is to develop hybrid ABMs to understand the transmission dynamics of vector-borne diseases such as Dengue, Zika, and Chikungunya considering some geospatial characteristics of the city of Bello, Colombia. Some assumptions were considered to develop the computational model to understand and verify if the transmission dynamics were happening according to their theoretical behavior. The results obtained were satisfactory, and for future work, the idea is to integrate more components and make the model more realistic.

Design of scaled model for dynamic characteristics of stiffened cylindrical shells based on equivalent similar method

2019 ◽  
Vol 123 (1261) ◽  
pp. 398-415 ◽  
Author(s):  
L. L. Zhou ◽  
D. K. Li
Keyword(s):  
Cylindrical Shell ◽  
Model Test ◽  
Scaling Laws ◽  
Effective Means ◽  
Scaled Model ◽  
Numerical Examples ◽  
Stiffened Cylindrical Shell ◽  
Bending Mode ◽  
Scaled Models ◽  
Stiffened Cylindrical Shells

ABSTRACTScaled model test is an effective means to verify the design of a stiffened cylindrical shell. However, there is a problem of similarity distortion by use of the traditional dimensional analysis to design scaled models. In this present study, an equivalent similar method is proposed to solve the problem. The method is applied to an axial stiffened cylindrical shell, and the equivalent criteria and scaling laws satisfying the equivalent similarity of global bending mode are derived and verified by numerical examples. The results indicate that the similarity distortion caused by practical conditions for the stiffened cylindrical shell can be solved and the parameters of scaled model can be designed more freely with the proposed equivalent similar method.

scholarly journals Sequential lidar sensor system simulation: a modular approach for simulation-based safety validation of automated driving

2020 ◽  
Vol 5 (3-4) ◽  
pp. 187-197
Author(s):  
Philipp Rosenberger ◽  
Martin Friedrich Holder ◽  
Nicodemo Cianciaruso ◽  
Philip Aust ◽  
Jonas Franz Tamm-Morschel ◽  
...  
Keyword(s):  
Simulation Models ◽  
Point Clouds ◽  
Autonomous Driving ◽  
Modular Approach ◽  
Active Perception ◽  
Automated Driving ◽  
Test Procedures ◽  
Sequential Approach ◽  
Simulation Based ◽  
Tracking Model

Abstract Validating safety is an unsolved challenge before autonomous driving on public roads is possible. Since only the use of simulation-based test procedures can lead to an economically viable solution for safety validation, computationally efficient simulation models with validated fidelity are demanded. A central part of the overall simulation tool chain is the simulation of the perception components. In this work, a sequential modular approach for simulation of active perception sensor systems is presented on the example of lidar. It enables the required level of fidelity of synthetic object list data for safety validation using beforehand simulated point clouds. The elaborated framework around the sequential modules provides standardized interfaces packaging for co-simulation such as Open Simulation Interface (OSI) and Functional Mockup Interface (FMI), while providing a new level of modularity, testability, interchangeability, and distributability. The fidelity of the sequential approach is demonstrated on an everyday scenario at an intersection that is performed in reality at first and reproduced in simulation afterwards. The synthetic point cloud is generated by a sensor model with high fidelity and processed by a tracking model afterwards, which, therefore, outputs bounding boxes and trajectories that are close to reality.

scholarly journals Does the Budyko curve reflect a maximum-power state of hydrological systems? A backward analysis

2016 ◽  
Vol 20 (1) ◽  
pp. 479-486 ◽  
Author(s):  
M. Westhoff ◽  
E. Zehe ◽  
P. Archambeau ◽  
B. Dewals
Keyword(s):  
Maximum Power ◽  
Actual Evaporation ◽  
Run Off ◽  
Maximum Power Principle ◽  
State Behaviour ◽  
Backward Analysis ◽  
Almost All ◽  
Future Work ◽  
Principle Of Maximum ◽  
Organizing Principles

Abstract. Almost all catchments plot within a small envelope around the Budyko curve. This apparent behaviour suggests that organizing principles may play a role in the evolution of catchments. In this paper we applied the thermodynamic principle of maximum power as the organizing principle. In a top-down approach we derived mathematical formulations of the relation between relative wetness and gradients driving run-off and evaporation for a simple one-box model. We did this in an inverse manner such that, when the conductances are optimized with the maximum-power principle, the steady-state behaviour of the model leads exactly to a point on the asymptotes of the Budyko curve. Subsequently, we added dynamics in forcing and actual evaporation, causing the Budyko curve to deviate from the asymptotes. Despite the simplicity of the model, catchment observations compare reasonably well with the Budyko curves subject to observed dynamics in rainfall and actual evaporation. Thus by constraining the model that has been optimized with the maximum-power principle with the asymptotes of the Budyko curve, we were able to derive more realistic values of the aridity and evaporation index without any parameter calibration. Future work should focus on better representing the boundary conditions of real catchments and eventually adding more complexity to the model.

Effect of Load Frequency on Dynamic Similitude of Scaled Model

2013 ◽  
Vol 448-453 ◽  
pp. 3508-3513
Author(s):  
Yu Chao Song ◽  
Yan Nian Cai ◽  
Chao Ming Huang ◽  
Hong Liang Yu
Keyword(s):  
Finite Element Method ◽  
Scaled Model ◽  
Test Analysis ◽  
Modal Theory ◽  
Load Frequency ◽  
Model Dynamics ◽  
Prototype Structure ◽  
Key Factor ◽  
Dynamic Similitude ◽  
Model Structures

The similitude requirement of excited load was deduced to maintain the consistent vibration between scaled model and prototype structure, based on the modal theory of multi-DOFs systems. The similitude of load frequency was another demand to maintain the consistent vibration, with the similitude of structure size and load magnitude. The dynamic similitude problem of a liquid tank was studied by finite element method and test analysis respectively. The results show that the similitude of load frequency is the insurance for the consistency of prototype and scaled model structures vibration. In a case the magnitude error of displacement is 8% to 10%, and the displacement and acceleration have all changed distinctly without the similitude of load frequency. All the results indicate that the similitude of load frequency is the key factor to analyze the scaled model dynamics correctly.

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