scholarly journals Evaluation of the Volume Measurement Optical Method Suitability for Determining the Relative Compaction of Soils

2018 ◽  
Vol 4 (9) ◽  
pp. 2052
Author(s):  
Karol Brzeziński ◽  
Maciej Maślakowski ◽  
Paweł Liszewski
Keyword(s):  
Statistical Analysis ◽  
Optical Method ◽  
Three Dimensional ◽  
Volume Measurement ◽  
Operating Conditions ◽  
Relative Compaction ◽  
Statistical Dispersion ◽  
Three Dimensional Models ◽  
Two Stages ◽  
Method Suitability

The goal of this paper is evaluation of the volume measurement optical method suitability for determining relative compaction of soils. The Structure for Motion technique was utilized in order to achieve the goal by making the three-dimensional models (with Bentley ContextCapture software). Created models were used in volume measurement of the pit-holes. The results were compared with the basic methods: the sand cone test and the water method. The laboratory tests were carried out in two stages. In the first stage, the optical method was tested in similar to operating conditions. Ten holes were made in the soil and the volumes were measured with three different methods. The results were compared and submitted for statistical analysis. Statistical analysis showed the potential of optical method. The second laboratory test focused on repeatability and accuracy of measurement. The volume of the vessel imitating a pit-hole was obtained. The results of the second stage showed that the optical method has better accuracy and lower statistical dispersion compared with sand method. On this basis it can be concluded that optical method of volume measurement has great potential in soil compaction testing.

Development and validation of a novel quasi-dimensional combustion model for un-scavenged prechamber gas engines with numerical simulations and engine experiments

2020 ◽  
pp. 146808742095133 ◽  
Author(s):  
Konstantinos Bardis ◽  
Panagiotis Kyrtatos ◽  
Guoqing Xu ◽  
Christophe Barro ◽  
Yuri Martin Wright ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Design Parameters ◽  
Combustion Model ◽  
Experimental Investigations ◽  
Computationally Efficient ◽  
Lean Burn ◽  
Dimensional Models ◽  
Three Dimensional Models

Lean-burn gas engines equipped with an un-scavenged prechamber have proven to reduce nitrogen oxides (NOx) emissions and fuel consumption, while mitigating combustion cycle-to-cycle fluctuations and unburned hydrocarbon (UHC) emissions. However, the performance of a prechamber gas engine is largely dependent on the prechamber design, which has to be optimised for the particular main chamber geometry and the foreseen engine operating conditions. Optimisation of such complex engine components relies partly on computationally efficient simulation tools, such as quasi and zero-dimensional models, since extensive experimental investigations can be costly and time-consuming. This article presents a newly developed quasi-dimensional (Q-D) combustion model for un-scavenged prechamber gas engines, which is motivated by the need for reliable low order models to optimise the principle design parameters of the prechamber. Our fundamental aim is to enhance the predictability and robustness of the proposed model with the inclusion of the following: (i) Formal derivation of the combustion and flow submodels via reduction of the corresponding three-dimensional models. (ii) Individual validation of the various submodels. (iii) Combined use of numerical simulations and experiments for the model validation. The resulting model shows very good agreement with the numerical simulations and the experiments from two different engines with various prechamber geometries using a set of fixed calibration parameters.

scholarly journals Prediction of Film Cooling Effectiveness of Steam

1982 ◽  
Author(s):  
Je-Chin Han ◽  
P. E. Jenkins
Keyword(s):  
Film Cooling ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Air Cooling ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Gas Turbine Blades ◽  
Fluid Properties ◽  
Three Dimensional Models

The intent of this work is to show, analytically, that superheated steam can provide better film cooling than conventional air for gas turbine blades and vanes. Goldstein’s two-dimensional and Eckert’s three-dimensional models have been reexamined and modified in order to include the effects of thermal-fluid properties of foreign gas injection on the film cooling effectiveness. Based on the modified models, the computed results for steam film cooling effectiveness, showing an increase of 80 to 100 percent when compared with air cooling at the same operating conditions, are presented.

Numerical Simulations of the Fluid Flow and Heat Transfer during a Solidification Phase Change of a Polymer in a Die

2010 ◽  
Vol 97-101 ◽  
pp. 2736-2743
Author(s):  
Shi Xiong Ren ◽  
Sha Sha Dang ◽  
Tao Lu ◽  
Kui Sheng Wang
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Liquid Volume ◽  
Liquid Volume Fraction ◽  
Three Dimensional Models ◽  
Lower Temperature ◽  
Thermal Oil

Three-dimensional models of heat transfer have been established and numerically solved using a commercial software package, Fluent, in order to obtain distributions of temperature, velocity, pressure, and liquid volume fraction of the polymer. The influences of the boundary conditions on the phase change of the polymer and the temperature distribution in the die have been evaluated. The results show that the temperature of the region close to the pelletizing surface is relatively low due to the cooling effect of the cool water, while the temperature deeper inside the die is higher, with a lower temperature gradient, as a result of the heating effect of the hot thermal oil and the polymer. A solidification phase change of the polymer occurs near the polymer outlet due to heat loss from the polymer to the water, while deeper inside the hole the polymer remains fluid without solidification, due to heating by the thermal oil. Numerical simulation provides a reliable method to optimize the design of the die, the choice of metallic material for the die, and the operating conditions of the polymer pelletizing under water.

scholarly journals Study on airflow and vibraton in a cutting/collection/discharge lawn care system

2021 ◽  
Author(s):  
Evan D. Davidge
Keyword(s):  
Three Dimensional ◽  
Operating Conditions ◽  
Two Dimensional ◽  
Discharge System ◽  
Rotating Blades ◽  
Lawn Care ◽  
Optimal Shapes ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Care System

Airflows in the cutting/collection/discharge system of a professional lawn care system were studied numerically and experimentally in this thesis. Various three-dimensional and two-dimensional computational fluid dynamics models were developed in order to investigate the complex airflow created by a pair of counter-rotating blades. The three-dimensional models were used to study the actual flows; the two-dimensional models were developed to investigate the optimal shapes of the rotating blades using the mass flow rate per unit power consumption as the objective function. Experiments were carried out mainly to validate the computer models developed in this study for airflow velocity and power usage for an actual cutting system. Vibrations of a cutting blade were studied using the finite element method and experiments. It was found that the blades will experience resonance under normal operating conditions.

scholarly journals Study on airflow and vibraton in a cutting/collection/discharge lawn care system

2021 ◽  
Author(s):  
Evan D. Davidge
Keyword(s):  
Three Dimensional ◽  
Operating Conditions ◽  
Two Dimensional ◽  
Discharge System ◽  
Rotating Blades ◽  
Lawn Care ◽  
Optimal Shapes ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Care System

Airflows in the cutting/collection/discharge system of a professional lawn care system were studied numerically and experimentally in this thesis. Various three-dimensional and two-dimensional computational fluid dynamics models were developed in order to investigate the complex airflow created by a pair of counter-rotating blades. The three-dimensional models were used to study the actual flows; the two-dimensional models were developed to investigate the optimal shapes of the rotating blades using the mass flow rate per unit power consumption as the objective function. Experiments were carried out mainly to validate the computer models developed in this study for airflow velocity and power usage for an actual cutting system. Vibrations of a cutting blade were studied using the finite element method and experiments. It was found that the blades will experience resonance under normal operating conditions.

scholarly journals The influence of the last stage blades swirl to the efficiency of «stage-diffuser» unit of stationary GTU

2021 ◽  
Vol 23 (4) ◽  
pp. 84-95
Author(s):  
L O. Vokin ◽  
E Yu Semakina ◽  
V. A. Chernikov
Keyword(s):  
Vortex Flow ◽  
Three Dimensional ◽  
Experimental Methods ◽  
Operating Conditions ◽  
Dynamic Calculation ◽  
Three Dimensional Flow ◽  
Optimal Flow ◽  
Numerical Studies ◽  
Last Stage ◽  
Two Stages

THE PURPOSE. Determination of the optimal law of swirling of the blades of the last stage of a stationary GTU. Due to the specificity of its operating conditions - in a system with a diffuser - the traditional laws of swirling lead to a non-optimal flow in the diffuser and, consequently, reduce the efficiency of the entire unit and the power plant as a whole. In this paper, we used numerical and experimental methods for studying a three-dimensional flow. Two stages with different laws of swirling were investigated - with the traditional law of constancy of the angle of flow out of the guide vanes along the radius, and with reverse swirling. The same diffuser was used in both cases. METHODS. Experimental studies were carried out using pneumometric five-channel probes of an original design on an ET-4 aerodynamic stand in the Turbomachinery laboratory of SPbPU. Numerical studies were carried out in the CFX gas dynamic calculation package; the parameters in the corresponding sections, obtained during the physical experiment, were used as boundary conditions.RESULTS. Integral characteristics of the stage, the vector of flow velocities in various sections were obtained. The experiment was compared with the numerical calculation and showed satisfactory convergence of the results. CONCLUSION. The optimal swirling law for the last stage operating in a system with a diffuser is forced vortex flow.

Analysis of Dynamic Characteristics of Excavator Working Device Based on ANSYS+Pro/E

2014 ◽  
Vol 971-973 ◽  
pp. 372-375
Author(s):  
Di Zhao ◽  
Wei Yang ◽  
Qian Jin Liu ◽  
Xiao Hui Jin ◽  
Sheng Xu
Keyword(s):  
Dynamic Characteristics ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Mode Shapes ◽  
Element Analysis ◽  
Structural Dynamic ◽  
The Finite Element Analysis ◽  
Structural Dynamic Characteristics ◽  
Three Dimensional Models ◽  
Working Device

Complex operating environment makes excavator working device become the main wearing parts ,In this paper,builds three-dimensional models of the excavator working device using Pro/E. And selects the working device typical operating conditions which is in the maximum discharge height ,then imports it into the finite element analysis software ANSYS - Workbench module. For the purpose of acquiring its natural frequencies and mode shapes, it conducts the modal analysis by setting the material properties, meshing and boundary conditions,which provided foundation for the optimal design of hydraulic excavator overall vibration analysis and structural dynamic characteristics.

Plastic replicas as three-dimensional models of pulps

1975 ◽  
Vol 39 (8) ◽  
pp. 544-546
Author(s):  
HL Wakkerman ◽  
GS The ◽  
AJ Spanauf
Keyword(s):  
Three Dimensional ◽  
Dimensional Models ◽  
Three Dimensional Models

Validation of a Belt Model for Prediction of Hub Forces from a Rolling Tire4

2009 ◽  
Vol 37 (2) ◽  
pp. 62-102 ◽  
Author(s):  
C. Lecomte ◽  
W. R. Graham ◽  
D. J. O’Boy
Keyword(s):  
Internal Pressure ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Prediction Method ◽  
Analytical Models ◽  
Beam Model ◽  
Impedance Boundary ◽  
Bending Waves ◽  
Tire Rotation ◽  
Three Dimensional Models

Abstract An integrated model is under development which will be able to predict the interior noise due to the vibrations of a rolling tire structurally transmitted to the hub of a vehicle. Here, the tire belt model used as part of this prediction method is first briefly presented and discussed, and it is then compared to other models available in the literature. This component will be linked to the tread blocks through normal and tangential forces and to the sidewalls through impedance boundary conditions. The tire belt is modeled as an orthotropic cylindrical ring of negligible thickness with rotational effects, internal pressure, and prestresses included. The associated equations of motion are derived by a variational approach and are investigated for both unforced and forced motions. The model supports extensional and bending waves, which are believed to be the important features to correctly predict the hub forces in the midfrequency (50–500 Hz) range of interest. The predicted waves and forced responses of a benchmark structure are compared to the predictions of several alternative analytical models: two three dimensional models that can support multiple isotropic layers, one of these models include curvature and the other one is flat; a one-dimensional beam model which does not consider axial variations; and several shell models. Finally, the effects of internal pressure, prestress, curvature, and tire rotation on free waves are discussed.

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