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Most wind tunnel models are fabricated of all metal components using computerized numerical control (CNC) milling machines.
Fabrication of metal wind tunnel models is very expensive and time consuming. The models can require months to manufacture
and are often made by small high technology companies that specialize in wind tunnel model manufacture....
Similar publications
Rapid Prototyping Technology (RPT) is a feasible and alternative productive approach for manufacturing sector to reduce time and cost by creating mathematical (CAD) model of the product to be built. The primary aim of this review is to provide platform to researchers to gain information about which rapid prototyping material and process is sufficie...
![Fig. 1. Schematic diagram of FDM process [15]](profile/Saeed-Daneshmand/publication/258498356/figure/fig1/AS:11431281184235526@1693262414300/Schematic-diagram-of-FDM-process-15_Q320.jpg)
Casting, machining and additive manufacturing technologies are used in order to produce wind tunnel testing models. The models can also be analyzed by computational fluid dynamics methods. Both have their advantages and disadvantages. Since several wind tunnel models are required to accomplish aerodynamic experiments, nowadays, one of the best meth...
Citations
... Although the hybrid model improved its overall strength, their model required additional treatments to strengthen the interface adhesion between the metal and the SLA parts. Daneshmand et al. [13] experimentally investigated the wingbody-tail model developed using the FDM process with and without chromium coating for subsonic wind tunnel testing. They compared these two models with a traditional steel model and reported that the FDM model without coating produced unsatisfactory results due to increased surface roughness. ...
Developing wind tunnel models is time consuming, labor intensive, and expensive. Rapid prototyping for wind tunnel tests is an effective, faster, and cheaper method to obtain aerodynamic performance results while considerably reducing acquisition time and cost for the models. Generally, the rapid prototyping models suffer from insufficient stiffness or strength to withstand the loads generated during a wind tunnel test. In the present study, a rapid prototype model reinforced with metallic inserts was produced to experimentally investigate the aerodynamic characteristics of an uncrewed aerial vehicle with various wingtip deflections. The fused deposition modeling process was used to make the outer mold, whereas the metallic parts were produced using laser cutting and the computer numerical control machining process. Then, the model was evaluated both experimentally and numerically. The test campaign presented in this work was conducted in the de Havilland low-speed wind tunnel facility at the University of Glasgow. For better characterization of flow patterns dominated by leading edge vortices, numerical simulations were run using OpenFOAM 8.0 and validated with experimental data. The experimental data obtained from the hybrid rapid-prototyped model agreed well with the numerical results. This demonstrates the efficacy of hybrid rapid-prototyped models in providing reliable results for initial baseline aerodynamic database development within a short period and at a reduced cost for wind tunnel tests.
... In this method, a printed sample with electroless nickel plating was utilized as a casting pattern to fabricate a cavity insert injection mold for the small-volume fabrication of polymeric products. Daneshmand et al. [21] and Equbal and Sood [22] also used the electroless metallization principle as their post-processing technique. Their method included a complicated surface conditioning, which consisted of acid etching and a layer of palladium coating in [21], or cleaning/purifying, acid etching, neutralization, activation, and acceleration sub-steps in [22], and electroless deposition. ...
... Daneshmand et al. [21] and Equbal and Sood [22] also used the electroless metallization principle as their post-processing technique. Their method included a complicated surface conditioning, which consisted of acid etching and a layer of palladium coating in [21], or cleaning/purifying, acid etching, neutralization, activation, and acceleration sub-steps in [22], and electroless deposition. However, the thermal property of the treated samples was not shown. ...
Fused deposition modeling (FDM) is categorized in additive technology where prototypes and functional components are fabricated with no limitation of shape complexity and shorter part development time. However, besides its great advantages, its layer-by-layer fabrication has a weakness of poor surface roughness, and its plastic materials have low thermal conductivity. While there have been a lot of studies of the surface roughness in FDM, it is still required to solve the thermal problem that prevents FDM from being applied in manufacturing processes incorporating heating, such as thermoforming. In this paper, a new post-processing method for FDM-3D printed moldcore is experimentally investigated for surface finish improvement and heat absorption reduction to broaden the application scope of FDM. The Taguchi method in conjunction with a lumped-capacitance model is used in respect of multi-input and single-output (MISO). The results show that a chemical treatment using dimethylketone (acetone) improved the surface roughness while aluminum spray coating decreased heat absorption of the FDM’s samples using acrylonitrile–butadiene–styrene (ABS) filament. The dimensional variation during this process is also confirmed to be very small. This low-cost post-processing technique is found to be easily applied on both lab-scale and manufacturing scales, especially for low-volume production or prototype fabrication.
... Currently, all used model-making technologies can be divided into three broad categories: -Additive technology (3D printing) [9][10][11][12][13], in which during the manufacturing process the material is added to the workpiece or base to obtain a finished model; ...
The features of 3D printing method for rapid prototyping and manufacturing of models for a pulsed high-speed gas-dynamic experiment are considered. Modern additive technologies allow the production of models. The basic properties of the materials and the advantages of 3D printing methods are described. The structure and properties of the obtained models can be unattainable using traditional manufacturing techniques. The design of the wind tunnel nozzle block is considered, which provides for the production of profiled contours using 3D printing. The advantages and disadvantages of use of such units on the shock tube are considered.
... where is the viscosity, is a constant factor, and 1 is the viscosity of the oil at ambient temperature. Equations (20) are solved using the Newton method, which is as follows 24 ...
In this paper, multi-objective particle swarm optimization method is developed for optimizing thermo-hydrodynamic journal bearings. This paper focuses on the use of multi-objective particle swarm optimization algorithm with a combination of the thermal hydrodynamic governing equations of the fluid film (i.e. momentum and energy equations) to optimize hydrodynamic partial pad journal bearings and compare with other articles. The governing equations are solved by the central difference method with a successive over-relaxation scheme and the backward difference with an iterative technique. In the paper, the lubricant viscosity changes with the temperature variation in whole fluid film. In this optimization, the bearing power loss, the minimum oil film thickness, and the maximum oil temperature are considered as objective functions and the radial clearance and length to diameter ratio are selected as design variables. The results of the objective functions are compared to other articles. Also, this study discusses the entropy and availability of two concentric cylinders with low curvature and constant wall temperature. Calculations showed that by increasing the Eckert number, the availability increases.
... To overcome the thermal problem associated with RP parts, an indirect rapid tooling approach based on the RP technology is presented in Rajaguru et al. (2015) where a printed model coated with electroless-plated nickel was used as a casting pattern to build a cavity insert in an injection mold for lowvolume production of plastic parts. Sood (2014, 2015) and Daneshmand et al. (2010) used the same principle of electroless metallization, including surface conditioning and electroless deposition as the post-processing technique. It is worth noting that the surface conditioning step was a combination of cleaning, acid etching, neutralization, activation and acceleration sub-steps (Equbal and Sood, 2015) or acid etching and a palladium coating (Daneshmand et al., 2010). ...
... Sood (2014, 2015) and Daneshmand et al. (2010) used the same principle of electroless metallization, including surface conditioning and electroless deposition as the post-processing technique. It is worth noting that the surface conditioning step was a combination of cleaning, acid etching, neutralization, activation and acceleration sub-steps (Equbal and Sood, 2015) or acid etching and a palladium coating (Daneshmand et al., 2010). Zhou et al. (2008) used an electrodeposited nickel coating to improve the overall strength and stiffness of SL parts. ...
Purpose
The purpose of this paper is to develop a novel post-processing technique of fused deposition modeling (FDM) parts to improve surface roughness and reduce heat absorption and for high-temperature application in thermoforming process.
Design/methodology/approach
The current technique consists of chemical treatment, drying and aluminum coating. First, surface morphology was investigated using FDM specimens with a flat surface. The heat absorption characteristic was also analyzed by Taguchi-based design of experiment and modified lump-capacity model. In addition, dimensional accuracy and uniformity were investigated under high-temperature conditions, which were similar to a typical thermoforming process, with specimens having concave and convex grooves.
Findings
It was verified that the proposed post-processing technique could efficiently improve surface quality of FDM parts with the arithmetic average surface roughness of 2.06 µm. In addition, the coated aluminum layer was found to reflect the heat radiation, resulting into a sufficient reduction of heat absorption. From the investigation of dimensional accuracy and uniformity, it was found that the current technique produced maximum change of 0.11 mm and uniform thickness of an aluminum layer within 0.07 mm.
Originality/value
The present study establishes a novel post-processing technique, enabling to treat the surface of FDM parts for high-temperature applications. It provides a simple way of using typical FDM parts for a thermoforming process as the mold cores. Furthermore, it can be used in other rapid tooling technologies, consequently widening the application areas of FDM.
... The parts can also be improved using coating method by another chemical agent and improved the surface finishing as well as its mechanical strength [21,22]. The vapor smoothing is usually conducted using hot vapor and it can be conducted for the complex shape such as medical appliances [23,24].Chemical vapor acts as a solvent to smooth the outer layer of the parts and improves the surface finishing especially on ABS parts [25]. Various analysis to find the optimum setting for several parameter conditions of vapor smoothing including quantitative analysis using central composite design (CCD's) experiment, design of experiment (DOE) using Taguchi and experimental design between the parameter settings for FDM and vapor smoothing conditions were conducted [11]. ...
Fused deposition modeling (FDM) is a 3D printing/additive manufacturing (AM) technology that creates a part layer by layer. However, the printed parts have poor surface finish and staircase effect, which is the inherent characteristics of FDM printed parts. This contributes to poor quality of the final components. Thus, in this paper, post process treatment on 3D printed part by using blow cold vapor has been made. The parts were fabricated by using the open-source 3D printer with acrylonitrile-butadiene-styrene (ABS) material. Then, after the treatment, the surface finish and the mechanical properties of the parts were analyzed. The cold vapor treatment using chemical agents, namely acetone and methyl-ethyl-ketone (MEK). A comparison was made between the parts before and after treatment. It is found that the proposed method is able to improve the surface finishing of FDM parts. However, the method has affected the tensile strength where there is a slight decrease in the strength value.
... Initial and final readings depicted negligible dimensions changes with extremely smooth surface. Daneshmand et al. (2010) and Daneshmand and Aghanajafi (2012) fabricated wind tunnel models using FDM to reduce cost and fabrication times. Models used without surface finishing do not produce satisfactory results because the highly smooth surface is required for high speed testing. ...
Purpose
The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling (FDM)-based acrylonitrile butadiene styrene (ABS) prototypes. FDM being simple and versatile additive manufacturing technique has a calibre to comply with present need of tailor-made and cost-effective products with low cycle time. But the poor surface finish and dimensional accuracy are the primary hurdles ahead the implementation of FDM for rapid casting and tooling applications.
Design/methodology/approach
The consequences and scope of FDM pre-processing and post-processing parameters have been studied independently. The comprehensive study includes dominance, limitations, validity and reach of various techniques embraced to improve surface characteristics of ABS parts. The replicas of hip implant are fabricated by maintaining the optimum pre-processing parameters as reviewed, and a case study has been executed to evaluate the capability of vapour smoothing process to enhance surface finish.
Findings
The pre-processing techniques are quite deficient when different geometries are required to be manufactured within limited time and required range of surface finish and accuracy. The post-processing techniques of surface finishing, being effective disturbs the dimensional stability and mechanical strength of parts thus incapacitates them for specific applications. The major challenge for FDM is the development of precise, automatic and controlled mass finishing techniques with low cost and time.
Research limitations/implications
The research assessed the feasibility of vapour smoothing technique for surface finishing which can make consistent castings of customized implants at low cost and shorter lead times.
Originality/value
The extensive research regarding surface finish and dimensional accuracy of FDM parts has been collected, and inferences made by study have been used to fabricate replicas to further examine advanced finishing technique of vapour smoothing.
... In aerodynamic experiment a crucial factor is proper preparation of tested elements surface. Various 3D printing techniques provides different quality and surface finish which is not always acceptable for certain application [2]. The following paper attempts to review chosen properties of rough 3D printouts and analyse them. ...
... Today ABS can be plated with metals which can retain their luster and shape for several years. The current market for plating of ABS is great and a significant amount of research is being carried out across the world on ABS-like materials with regard to surface preparation and deposition of metal or metal composites [33,34,39,41,53,[82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100]. As represented in the flowchart (Fig. 3), conventional electroplating on ABS process can be divided into two important steps: surface preparation and metal plating. ...
ABS is an engineering plastic that has butadi-ene part uniformly distributed over the acrylonitrile-styrene matrix. It possesses excellent toughness, good dimensional stability, easy processing ability, chemical resistance, and cheapness. However, it suffers from inherent shortcomings in terms of mechanical strength and vulnerability to environmental conditions. Furthermore, it is non-conducting and easily fretted. Plating on ABS can serve to enhance the strength and structural integrity as well as to improve durability and thermal resistance resulting in metallic properties on the ABS material. ABS is described as the most suitable candidate for plating because it is possible to deposit an adherent metal coating on it by only the use of chemical pretreatment process and without the use of any mechanical abrasion. This article aims to review the history of ABS plastics, properties of ABS, processes and mechanisms of plating, and studies of plating on ABS involving mainly eco-friendly methods of plating by discussing the literature published in recent years. The details of elec-troplating of ABS carried out in the authors' laboratory are also presented.
... Cost saving and model design/fabrication time reduction over a factor of five has been realized for RPT techniques as compared to the current standard model design/fabrication practices. In [3] FDM model with chromium coating was shown best result for majority of the test conditioning compared to initial FDM model because of surface roughness of initial model. Cost saving and model design/fabrication time reduction over a factor of two has been realized for RPT techniques as compared to the current standard model design/fabrication practices. ...
... From reference [3], Researchers are using chromium coating in RP technology for airfoil manufacturing. In this paper authors discusses the application of wind tunnel model configuration constructed using FDM and FDM with chromium coating for subsonic wind tunnel testing. ...
Rapid Prototyping Technology (RPT) is a feasible and alternative productive approach for manufacturing sector to reduce time and cost by creating mathematical (CAD) model of the product to be built. The primary aim of this review is to provide platform to researchers to gain information about which rapid prototyping material and process is sufficient for constructing wind tunnel models and if these models meets the structural requirements of subsonic testing while still having the high fidelity required to produce accurate aerodynamic data for educational purpose (Preliminary Design Study) with low budget. Subsequently this paper deals with time reduction and cost effectiveness of rapid prototyping in aerospace industry.
