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Article

Elham Mohammadi and Alireza Toloei

The purpose of this paper is to analyze the flowfield structure and performance of dual secondary injection system for thrust vectoring in a convergent‐divergent nozzle…

Abstract

Purpose

The purpose of this paper is to analyze the flowfield structure and performance of dual secondary injection system for thrust vectoring in a convergent‐divergent nozzle and to compare it with a single secondary injection system.

Design/methodology/approach

Dual secondary injection for thrust vectoring in a convergent‐divergent nozzle is studied by solving three‐dimensional Reynolds‐averaged Navier‐Stokes equations by the means of Fluent. Realizable k‐ε turbulent model with enhanced wall‐treatment approach is used for viscous model. Density‐based solver and explicit scheme are employed in the computational model. In order to study the effect of injection location on the flowfield, distance between ports is considered as the key variable.

Findings

Results show that under some circumstances, dual secondary injection system is more effective than a single injection system with the same mass flow rate. The study shows that when the distance between two ports is 8.5 times of the injection port's diameter (or more) and in the same time the first injection port is at least 1 throat diameter far from the nozzle throat, this system will show a better performance. In addition, this system reduces the probability of bow shock impingement to the opposite wall and consequently, the side force production has less limitation.

Practical implications

Dual secondary injection for thrust vector control (SITVC) needs less secondary flow and therefore it makes less reduction in the primary thrust. It means that for a specific primary thrust, less mass fuel is needed which makes it more economic regarding the traditional SITVC systems.

Originality/value

The paper's value lies in using a three‐dimensional model to study the effect of two ports distance on SITVC performance and comparison among the performance of dual and single injections when there is an impingement.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

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Article

Wu‐Lin Chen, Chin‐Yin Huang and Chi‐Wei Hung

The purpose of this paper is to find the optimal values of process parameters in injection molding when both warpage and shrinkage are minimized.

Abstract

Purpose

The purpose of this paper is to find the optimal values of process parameters in injection molding when both warpage and shrinkage are minimized.

Design/methodology/approach

In finding the optimal values, advantages of finite element software, Moldflow, and dual response surface method (dual RSM) combined with the nonlinear programming technique by Lingo are exploited. Considering the nine process parameters, injection time, injection pressure, packing pressure, packing time, cooling time, coolant temperature, mold‐open time, melting temperature and mold surface temperature, a series of mold analyses are performed to exploit the warpage and shrinkage data. In the analyses, warpage is considered the primary response, whereas shrinkage is the secondary response.

Findings

The results indicate that dual RSM combined with the nonlinear programming technique can outperform the Taguchi's optimization method. The optimal process values are also confirmed by re‐running experiments on Moldflow. Additionally, an auxiliary dual RSM model is proposed to search for a better result based on the given findings by dual RSM at the cost of running extra experiments. Based on dual RSM, a multiple objective optimization for the whole plastic product is finally suggested to integrate the dual RSM models that are developed for the individual nodes or edges.

Originality/value

This paper proposes a new method to find the optimal process for plastic injection molding.

Details

Engineering Computations, vol. 27 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

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Article

M. Grujicic, V. Sellappan, G. Arakere, J.M. Ochterbeck, Norbert Seyr, Andreas Obieglo, Marc Erdmann and Jochen Holzleitner

The purpose of this paper is to propose and analyse computationally a new concept for mechanical interlocking between metal and plastics. The approach utilizes some of the…

Abstract

Purpose

The purpose of this paper is to propose and analyse computationally a new concept for mechanical interlocking between metal and plastics. The approach utilizes some of the ideas used in the spot‐clinching joining process and is appropriately named “clinch‐lock polymer metal hybrid (PMH) technology.”

Design/methodology/approach

A new approach, the so‐called “direct‐adhesion” PMH technology, is recently proposed Grujicic et al. to help meet the needs of automotive original equipment manufacturers and their suppliers for a cost‐effective, robust, reliable PMH technology which can be used for the manufacturing of load‐bearing body‐in‐white (BIW) components and which is compatible with the current BIW manufacturing‐process chain. Within this approach, the necessary level of polymer‐to‐metal mechanical interconnectivity is attained through direct adhesion and mechanical interlocking.

Findings

In an attempt to fully assess the potential of the clinch‐lock approach for providing the required level of metal/polymer mechanical interlocking, a set of finite‐element based sheet‐metal forming, injection molding and structural mechanics analyses is carried out. The results obtained show that stiffness and buckling resistance levels can be attained which are comparable with those observed in the competing injection over‐molding PMH process but with an ∼3 percent lower weight (of the polymer subcomponent) and without the need for holes and for over‐molding of the free edges of the metal stamping.

Originality/value

The paper presents a useful discussion of clinch‐lock joining technology's potential for fabrication of PMH load‐bearing BIW components.

Details

Multidiscipline Modeling in Materials and Structures, vol. 6 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

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Article

Richard Bloss

Innovations in robots for plastics applications are moving in many directions. Two headed and up to six axis robots for faster unloading and secondary operations. Stand…

Abstract

Innovations in robots for plastics applications are moving in many directions. Two headed and up to six axis robots for faster unloading and secondary operations. Stand alone robot controllers are being replaced with control functions integrated into the controller for the injection moulding machine.

Details

Industrial Robot: An International Journal, vol. 31 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

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Article

Ganesh Rupchand Gawale and Naga Srinivasulu G.

Homogeneous charge compression ignition (HCCI) engine is an advanced combustion method to use alternate fuel with higher fuel economy and, reduce NOX and soot emissions…

Abstract

Purpose

Homogeneous charge compression ignition (HCCI) engine is an advanced combustion method to use alternate fuel with higher fuel economy and, reduce NOX and soot emissions. This paper aims to investigate the influence of ethanol fraction (ethanol plus gasoline) on dual fuel HCCI engine performance.

Design/methodology/approach

In this study, the existing CI engine is modified into dual fuel HCCI engine by attaching the carburetor to the inlet manifold for the supply of ethanol blend (E40/E60/E80/E100). The mixture of ethanol blend and the air is ignited by diesel through a fuel injector into the combustion chamber at the end of the compression stroke. The experiments are conducted for high load conditions on the engine i.e. 2.8 kW and 3.5 kW maximum output power for 1,500 constant rpm.

Findings

It is noticed from the experimental results that, with an increase of ethanol in the blends, ignition delay (ID) increases and the start of combustion is retarded. It is noticed that E100 shows the highest ID and low in-cylinder pressure; however, E40 shows the lowest ID compared to higher fractions of ethanol blends. An increase in ethanol proportion reduces NOX and smoke opacity but, HC and CO emissions increase compared to pure diesel mode engine. E100 plus diesel dual-fuel HCCI engine shows the highest brake thermal efficiency compared to remaining ethanol blends and baseline diesel engine.

Originality/value

This experimental study concluded that E100 plus diesel and E80 plus diesel gave optimum dual fuel HCCI engine performance for 2.8 kW and 3.5 kW rated power, respectively.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

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Article

Ken Young, Ian Pearson and R. Bull

A parameter has been identified that can be used to calculate a joint's bond‐line thicknesses. This was successfully represented by a fourth order polynomial expression…

Abstract

A parameter has been identified that can be used to calculate a joint's bond‐line thicknesses. This was successfully represented by a fourth order polynomial expression and has been used to predict the volume of adhesive required to precisely fill structural joints of unknown bond‐line thickness. This technology was further used to automatically control adhesive injection into pre‐assembled vehicle structural joints for use in an automated production environment. This has great advantage over adhesive application prior to joint assembly as the adhesive remains in the joint rather than contaminating the adherend surface and the bond‐line remains filled. This will be of benefit to the automotive industry. The method is adaptable and can be re‐programmed to cope with a number of applications.

Details

Assembly Automation, vol. 22 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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Article

M. Grujicic, G. Arakere, P. Pisu, B. Ayalew, Norbert Seyr, Marc Erdmann and Jochen Holzleitner

Application of the engineering design optimization methods and tools to the design of automotive body‐in‐white (BIW) structural components made of polymer metal hybrid…

Abstract

Application of the engineering design optimization methods and tools to the design of automotive body‐in‐white (BIW) structural components made of polymer metal hybrid (PMH) materials is considered. Specifically, the use of topology optimization in identifying the optimal initial designs and the use of size and shape optimization techniques in defining the final designs is discussed. The optimization analyses employed were required to account for the fact that the BIW structural PMH component in question may be subjected to different in‐service loads be designed for stiffness, strength or buckling resistance and that it must be manufacturable using conventional injection over‐molding. The paper demonstrates the use of various engineering tools, i.e. a CAD program to create the solid model of the PMH component, a meshing program to ensure mesh matching across the polymer/metal interfaces, a linear‐static analysis based topology optimization tool to generate an initial design, a nonlinear statics‐based size and shape optimization program to obtained the final design and a mold‐filling simulation tool to validate manufacturability of the PMH component.

Details

Multidiscipline Modeling in Materials and Structures, vol. 4 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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Article

Richard Bloss

This paper aims to present a review of the NPE 2006, Plastics Show held in Chicago, IL with emphasis on robots, their application in the plastics industry and end‐of‐arm‐tooling.

Abstract

Purpose

This paper aims to present a review of the NPE 2006, Plastics Show held in Chicago, IL with emphasis on robots, their application in the plastics industry and end‐of‐arm‐tooling.

Design/methodology/approach

In‐depth interviews with suppliers of robots, injection molding machines, system integration of robots into plastic processing applications, control suppliers and end‐of‐arm‐tooling.

Findings

The plastic injection molding industry is moving to production cells with heavy usage of robot machine tending. The need for very short cycle times drives the interest in very fast agile robots with the ability to integrate easily into the production cell approach. New technologies such as in mold labeling also drive the need for suitable robots and competent system integrators to supply successful systems.

Practical implications

Robot builders need to continue to develop specialized robots and tooling to match with advancements in applications in the plastic industry. Users will need to think of robots as a necessary adjunct to any injection molding application.

Originality/value

Presents a review of the NPE 2006, Plastics Show, Chicago, IL, with emphasis on robots, their application in the plastics industry and end‐of‐arm‐tooling.

Details

Industrial Robot: An International Journal, vol. 34 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

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Article

Richard Bloss

The purpose of this paper is to discuss how robot innovations as well as educational experiences are driving the more rapid deployment of automation into the manufacturing…

Abstract

Purpose

The purpose of this paper is to discuss how robot innovations as well as educational experiences are driving the more rapid deployment of automation into the manufacturing environment and other applications and reviewing the impact on employment.

Design/methodology/approach

In-depth interviews with builders and system integrators of automation equipment and conferring with users of robotics as well as attendance at conferences and trade shows addressing these topics.

Findings

Originally robots addressed only “heavy lifting” applications where cost and flexibility were very secondary considerations. Today users are looking to deploy robotic automation into all types of manufacturing and other applications where lower cost, two-armed flexibility and ease of programming are some of the very important considerations. Robotics are making manufacturers more competitive and growing thus creating more jobs, not costing jobs.

Practical implications

Customers may be surprised at the automation innovations and new applications which are appearing in the workplace and how easy they are to implement and deploy.

Originality/value

A review of and insight into some of the latest automation rapid deployment innovations and applications that have appeared recently as well as demonstrations of automation application at recent trade shows.

Details

Assembly Automation, vol. 33 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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Article

Khurram Altaf, Ahmad Majdi Abdul Rani and Vijay R. Raghavan

The purpose of this paper is to present a technique of fabricating profiled conformal cooling channels (PCCC) in an aluminium filled epoxy mould using rapid prototyping…

Abstract

Purpose

The purpose of this paper is to present a technique of fabricating profiled conformal cooling channels (PCCC) in an aluminium filled epoxy mould using rapid prototyping (RP) and rapid tooling (RT) techniques and to compare the cooling times for the moulds with circular and profiled channels experimentally. The cooling channels in injection mould tools have a circular cross section. In a PCCC, the cross sectional shape is so designed that the flat face surface of the channel facing the cavity follows the profile of the cavity. These types of channels can be manufactured through RP and RT techniques.

Design/methodology/approach

A part to be moulded was designed and modelled. Two moulds were then designed with the part cavity, one having a circular channel and the second with a profiled channel, both having the same cross sectional area for coolant flow. The channel patterns were designed with supports according to their position regarding height and distance from the cavity as designed earlier. Both channels have the same distance from the cavity wall. RP patterns were produced for both channels and part using the Thermojet 3D printer. The cooling channel and the moulded part patterns were then assembled as designed in the moulds. Moulding frames were fabricated with aluminium plates and the pattern was placed in the frames. Epoxy was poured on the pattern and then cured. The moulded part and the channel patterns embedded inside epoxy were melted out during the final curing cycle, leaving behind the circular‐ and profiled‐cooling channels in the moulds. For the cooling time measurement, injection moulding was done with moulds with circular and profiled channels. Moulded part temperature will be recorded by embedding thermocouples within the mould cavities.

Findings

A technique for the manufacture of cooling channels of different profiles in epoxy moulds was presented. Experimental analysis for temperature measurement for the moulded part with injection moulding process showed that PCCC mould has less cooling time then mould with circular channels.

Research limitations/implications

The technique presented is based on the metal‐filled epoxy materials used in RT and was obtained using a specific test part. Epoxy tooling can be a useful alternative of metallic mould to produce injection mould tools. A limitation for the epoxy moulds is that they have a limited life as compared with metallic moulds.

Originality/value

This is a new technique of manufacturing moulds with cooling channels using RP/RT techniques. Moulds with different channel cross sections can be manufactured using this technique.

1 – 10 of 277