Three-dimensional fatigue-based structural design optimisation of fuel flow vent holes

2009 ◽  
Vol 16 (1) ◽  
pp. 371-390 ◽  
Author(s):  
K. Krishnapillai ◽  
R. Jones ◽  
D. Peng
Keyword(s):  
Structural Design ◽  
Three Dimensional ◽  
Design Optimisation ◽  
Fuel Flow

scholarly journals A parametric design process model for box culverts

2021 ◽  
Vol 63 (3) ◽  
pp. 1-14
Author(s):  
N Ngobeni ◽  
A L Marnewick ◽  
D J Van Vuuren
Keyword(s):  
Design Process ◽  
Structural Design ◽  
Process Model ◽  
Parametric Design ◽  
Three Dimensional ◽  
Project Performance ◽  
Engineering Project ◽  
Design Optimisation ◽  
Box Culverts ◽  
Design Process Model

This research proposes a parametric design process model to improve the structural engineering project team performance by automating the design and three-dimensional modelling procedures of box culverts. Although standardised design procedures can reduce the design time of repetitive structures such as box culverts, the increased time and effort required for revising construction drawings negatively impacts a project's performance. A literature review was conducted to develop a theoretical process model to improve the current structural design optimisation and three-dimensional modelling procedures of box culverts. The proposed process model was validated using structured interviews with professionally registered structural engineers for appropriateness to box culverts and the potential to improve project performance. The data analysis revealed that the interviewed engineers were in favour of automating the design optimisation and three-dimensional modelling procedures of box culverts. Moreover, parametric design automation would result in improved project performance when encountering an inevitable design change. However, the user's control over the output of each process should not be discarded. This study can help readers understand the transformation of the structural design and three-dimensional modelling procedures of repetitive structures, such as box culverts, into an algorithmic form to achieve improved project performance.

scholarly journals Three-Dimensional Structural Design Using Local Rule

2005 ◽  
Vol 71 (705) ◽  
pp. 858-865
Author(s):  
Hironobu SAITO ◽  
Tatsuhiro TAMAKI ◽  
Hikaru SHIMIZU ◽  
Y. M. XIE ◽  
Eisuke KITA
Keyword(s):  
Structural Design ◽  
Three Dimensional ◽  
Local Rule

The Influence of Needle Eccentric Motion On Hole-to-Hole Injection Characteristics of a Two-Layered 8-Hole Diesel Injector

2021 ◽  
Author(s):  
Tianyu Jin ◽  
Yu Sun ◽  
Chuqiao Wang ◽  
Adams Moro ◽  
Xiwen Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Injection Rate ◽  
Hole Injection ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
Fuel Flow ◽  
Diesel Injection ◽  
Eccentric Motion

Abstract The stringent emission regulations diesel engines are required to meet has resulted in the usage of multi-hole and ultra-multi-hole injectors, nowadays. In this research study, a double layered 8-hole diesel injection nozzle was investigated both numerically and experimentally. A three-dimensional model of the nozzle which was validated with experimental results was used to analyze the injection characteristics of each hole. The validation was conducted by comparing experiment and simulation injection rate results, acquired simultaneously from all the holes of the injector and the model. The fuel flow rates of the lower layered holes are higher than those of the upper layered holes. Two different needle eccentricity models were established. The first model only included the lateral displacement of the needle during needle lift. The needle reached maximum displacement at full needle lift. The second model considered the needle inelastic deformation into consideration. The needle radially displaces and glides along with the needle seat surface during needle lift. When the eccentricity reached maximum in the radial direction, the needle began to lift upwards vertically. The differences in injection characteristics under the different eccentricity models were apparent. The results indicated that the cycle injection quantity, fuel injection rate and cavitation of each hole were affected during the initial lifting stages of the needle lift. As the eccentricity of the needle increases, the injection rate uniformity from the nozzle hole deteriorates. The result showed that the upper layered holes were affected by the needle eccentricity during needle lift.

An Accurate Performance Prediction of Solid Fuel Ramjets Using Coupled Intake-Combustor-Nozzle Simulation

2020 ◽  
Vol 36 (6) ◽  
pp. 933-941
Author(s):  
A. M. Tahsini
Keyword(s):  
Combustion Chamber ◽  
Solid Fuel ◽  
Solid Phase ◽  
Three Dimensional ◽  
Flow Fields ◽  
Reacting Flow ◽  
Computational Domain ◽  
Regression Rate ◽  
Fuel Flow ◽  
Accurate Performance

ABSTRACTThe performance of the solid fuel ramjet is accurately predicted using full part simulation of this propulsion system, where the flow fields of the intake, combustion chamber, and the nozzle are numerically studied all together. The conjugate heat transfer is considered between the solid phase and the gas phase to directly compute the regression rate of the fuel. The finite volume solver of the compressible turbulent reacting flow is utilized to study the axisymmetric three dimensional flow fields, and two blocks are used to discretize the computational domain. It is shown that the combustion chamber's pressure is changed due to the fuel flow rate's increment which must be taken into account in predictions. The results demonstrate that omitting the pressure dependence of the regression rate and also the effect of the combustor's inlet profile on the regression rate, which specially exists when simulating the combustion chamber individually, under-predicts the solid fuel burning rate when the regression rate augmentation technique is applied to improve the performance of the solid fuel ramjets. It is also illustrated that using the inlet swirl to increase the regression rate of the solid fuel augments considerably the thrust level of the considered SFRJ, while the predictions without considering all parts of the ramjet is not accurate.

Numerical Analysis of Ship Wave Loads and Structure Strengthen Analysis on a Wind Power Installation Ship

2011 ◽  
Vol 90-93 ◽  
pp. 2521-2527
Author(s):  
Gang Qiang Li ◽  
Yan Yan Zhao ◽  
Yong He Xie
Keyword(s):  
Wind Power ◽  
Structural Design ◽  
Three Dimensional ◽  
Load Condition ◽  
Wave Loads ◽  
Element Simulation ◽  
Wind Power Installation ◽  
Wave Induced ◽  
Term Response

In a typical load condition of wind power equipment Installation ship, using the three-dimensional potential flow theory to prediction the long-term response of wave induced loads. then using the main load control parameters as a basis for the design wave selection, then application of DNV's SESTRA program make the wave-induced directly to the structure to finite element simulation. The results show that the hull structural design can meet the requirements.

Assessment of LNG Pump Tower Loads

2019 ◽  
Author(s):  
Michael Thome ◽  
Jens Neugebauer ◽  
Ould el Moctar
Keyword(s):  
Structural Design ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Impact Loads ◽  
Detached Eddy Simulation ◽  
Morison Equation ◽  
Field Methods ◽  
Delayed Detached Eddy Simulation ◽  
Tower Structure

Abstract The assessment of design loads acting on Liquefied Natural Gas (LNG) pump tower are widely based on Morison equation. However, the Morison equation lacks consideration of transverse flow, impact loads and the interaction between fluid and structure. Studies dealing with a direct simulation of LNG pump tower loads by means of Computational Fluid Dynamics (CFD), which can cover the aforementioned effects, are currently not available. A comparative numerical study on LNG pump tower loads is presented in this paper focusing on the following two questions: Are impact loads relevant for the structural design of LNG pump towers? In which way does the fluid-structure interaction influence the loads? Numerical simulations of the multiphase problem were conducted using field methods. Firstly, Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations, extended by the Volume of Fluid (VoF) approach were used to simulate the flow inside a three-dimensional LNG tank in model scale without tower structure. The results were used to validate the numerical model against model tests. Motion periods and amplitudes were systematically varied. Velocities and accelerations along the positions of the main structural members of the pump tower were extracted and used as input data for load approximations with the Morison equation. Morison equation, URANS and Delayed Detached Eddy Simulation (DDES) computed tower loads were compared. Time histories as well as statistically processed data were used. Global loads acting on the full (with tower structure) and simplified structure (no tower structure, but using Morison equation) are in the same order of magnitude. However, their time evolution is different, especially at peaks, which is considered significant for the structural design.

Microcomputer analysis of reinforced concrete slab systems

1993 ◽  
Vol 20 (4) ◽  
pp. 587-601 ◽  
Author(s):  
Pierre Léger ◽  
Patrick Paultre
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Structural Design ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Equivalent Frame ◽  
Frame Method

Microcomputer finite element analysis of reinforced concrete slab systems can now be routinely performed to produce realistic numerical simulation of three-dimensional structural behaviour. However, an efficient use of this approach requires an automated integration of design and analysis procedures. Guidelines for proper finite element modelling of slab systems are first presented along with simple post-processing algorithms to perform automatically the design or verifications from the analytical results. Numerical applications on simple slab systems subjected to uniform and concentrated loads are then used to illustrate the relative performance between finite element analyses and the equivalent frame method. Key words: microcomputer, reinforced concrete slab, finite element method, structural design.

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