Fan optimization in industrial electric power tools

Industrial electric hammer. Source: Stanley Black & Decker/DeWALT

Development of modern electric power tools for professional applications requires simultaneous attention to two sets of product attributes: those that determine a tool’s efficiency and user comfort, and those that determine its robustness and durability. To optimize both sets of attributes together, Stanley Black & Decker Deutschland GmbH relies on computer-aided simulation using Altair’s AcuSolve CFD flow solver in combination with its HyperMorph mesh manipulation tool and HyperStudy multidisciplinary design exploration, study and optimization software. In a paper presented at the 2013 European Altair Technology Conference in Turin, Italy, the company described how these simulations were used throughout the product development cycle—from the pre-development phase, through testing near-series prototypes, and beyond to improving designs based on product-failure returns.

Objective: maximize cooling efficiency for optimal product performance and service life. Source: Stanley Black & Decker/DeWALT

“From the point of view of the performance and durability of our machines, it is our goal to design products to ever higher standards,” said Raúl Cano, Lead Project Engineer, CAE, for Stanley Black & Decker’s DeWALT Industrial Tool Co. brand. “To achieve and surpass the exacting requirements of our professional customers, one key factor is the cooling inside the machine.”

Alternate designs for cooling fan. Source: Stanley Black & Decker/DeWALT

Many factors together contribute to achieve the best cooling, Cano explained, including position of the openings for air ingress and egress, geometry of the product housing, geometry and fins of the gear housing, and of course the fan. “The latter is naturally of paramount importance because, depending on its position in the machine, the geometry of the fan’s fins and their position relative to the baffle could result in an increase or decrease of the air flow, the noise level, and the overall cooling effect.”

Fan performance comparison. Source: Stanley Black & Decker/DeWALT

“To understand and optimize these factors,” Cano continued, “AcuSolve has been successfully used to determine the amount of air flow.”

Increasing air flow allows increased motor power output. Source: Stanley Black & Decker/DeWALT
Influence of increased air flow on allowable motor power output. Source: Stanley Black & Decker/DeWALT

“Furthermore,” said Cano, “in combination with HyperStudy and HyperMorph, it is also possible to evaluate a huge number of designs—the results of which are used to assist the design engineers at Stanley Black & Decker to determine the key parameters that yield the best performance for cooling down the components inside the machine without wasting too much power from the motor.”

Fan optimization workflow. Source: Stanley Black & Decker/DeWALT
Finite element model for a 4kg hammer. Source: Stanley Black & Decker/DeWALT
Modeling fan parts for optimization. Source: Stanley Black & Decker/DeWALT
Simplified symmetric model for 4kg hammer—one fin model out of 17 fins total. Source: Stanley Black & Decker/DeWALT

To simplify the problem, Cano explained, first a single fin from the new fan design is modeled and studied. “Then you go with your optimized plan for the fan, put it inside the hammer, run a fluid simulation inside the hammer and see if the results are correct.”

Simplified symmetric model for 4kg hammer—faster way to evaluate the most influence parameters. Source: Stanley Black & Decker/DeWALT

With AcuSolve together with HyperMorph and HyperStudy, Cano reported, “we were able to achieve a ten percent increase in the air flow, which is a really good improvement in the cooling effect for the motor and other components.”

In addition to fan optimization, DeWALT also used Altair software for drop tests of its products. As a result, said Cano, “we improved our drop-test productivity substantially.” Formerly the company had used an outside lab for drop tests, a process that took six to eight weeks for each project. By adopting Altair software for this, “we took control,” said Cano. “Now we do all the meshing and analysis inside the company, and we reduced the time for a drop test to four weeks.”

“This is the best thing about Altair,” Cano summed up. “We go to them with our problems, and either they have the solutions, or they build a solution together with us. That is really nice—you don’t find that anywhere else.”

Bi-objective optimization of a waveguide


Waveguides are structures that guide electromagnetic waves, sound waves or other kinds of wave. Their function is to propagate a signal while minimizing energy loss by restricting its expansion to one dimension or two. A common application is signal transmission between components of a system such as a radio, radar, or other electronic or electro-optical device. This case involved bi-objective optimization of a waveguide for correct power split with minimal reflection loss. Continue reading

Aerodynamic optimization: Automotive engineering’s next strategic frontier

Source: Exa

With the unprecedented demands on today’s vehicle engineering organizations, auto makers face a daunting challenge to reach their next targets for aerodynamics drag using traditional tools and methods. Trial-and-error development using wind tunnel testing achieved a coefficient of drag of 0.3. Introducing digital simulation to sequentially improve designs brought CD down to 0.24 for today’s best performing cars. But most companies have the next target set to 0.2. Without either a radical increase in time and resources—not a realistic solution for most—or else a radically more efficient and effective approach to aerodynamics engineering, this target will remain all but out of reach. Continue reading

Structural optimization for automotive chassis weight reduction

Figure 1: Ferrari F458 Italia front hood: reference model and new layout from optimization results. The optimization was performed in three stages: topology, topometry and size. (a) Reference model, top view. (b) Reference model, bottom view. (c) Optimum layout. Source: MilleChili Lab

Executive summary—Improvements in design of vehicle structural components are often achieved through trial and error guided by the designer’s know-how. Although the designer’s experience must remain a fundamental element of design, this approach is likely to yield only marginal product enhancements. Design processes can be improved through structural optimization methods linked with finite element analysis. This study of weight reduction in automotive chassis design is based on approaches developed at MilleChili Lab, part of the MilleChili Project created by the University of Modena Engineering Faculty in collaboration with Ferrari to research and design a lightweight automotive chassis for high-performance cars. Continue reading

Weld and adhesive optimization in vehicle body structure development

Executive summary—Passenger-vehicle structural performance is extremely sensitive to welds and adhesive bonds. Traditionally, multidisciplinary optimization (MDO) has been performed largely using thickness, shape and material grade as variables. This project’s objective was to optimize the spot weld count and linear length of adhesives in the body while balancing vehicle structural performance and weight. Various optimization scenarios were carried out: maintain current structural performance but minimize weld count, adhesive length and body weight; maintain current weld count and adhesive length but maximize structural performance and minimize weight; and others. Including welds and adhesives as variables in the MDO process provided additional design space to improve structural performance and reduce cost through spot weld and adhesive minimization. Continue reading

Optimization at ANSYS Automotive Simulation World Congress

automotive-simulation-world-congressOptimization was a theme running throughout the 2015 Automotive Simulation World Congress organized by ANSYS last week in Detroit. We attended sessions on topology, structural, aerodynamic, adjoint, multi-objective and multidisciplinary optimization that ranged across all the conference tracks—Powertrain, Body & Interior, Chassis, Electrification & Electronics. Continue reading

RBF-based aerodynamic optimization of an industrial glider

Figure 1: Taurus glider

Executive summary—Improving the aerodynamic design of an industrial glider flying at Mach 0.08 was the goal of this project: RBF-based aerodynamic optimization of an industrial glider,” Emiliano Costa, D’Appolonia SpA, Rome, Italy; Marco E. Biancolini, Corrado Groth, University of Rome Tor Vergata, Rome, Italy; Ubaldo Cella, Design Methods (, Messina, Italy; Gregor Veble, Matej Andrejasic, Pipistrel d.o.o., Ajdovščina, Slovenia.

The original design exhibited performance-degrading separation in the wing-fuselage junction region at high incidence angles. Using a numerical optimization approach designed to be affordable even with limited HPC resources, the separation was significantly reduced by updating the local geometry of fuselage and fairing while maintaining the wing airfoil unchanged. Shape variations were applied to the glider’s baseline configuration through a mesh morphing technique founded on the mathematical framework of radial basis functions (RBFs). Computational outputs were obtained using a combination of ANSYS DesignXplorer, ANSYS Fluent and RBF Morph software working in the ANSYS Workbench environment. Continue reading

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