ANSYS Case Studies Engineering Simulation for Performance and Noise Reduction in Lawn Mowers: A Case Study of VIKING GmbH

	Engineering Simulation for Performance and Noise Reduction in Lawn Mowers: A Case Study of VIKING GmbH ANSYS

Engineering Simulation for Performance and Noise Reduction in Lawn Mowers: A Case Study of VIKING GmbH

ANSYS

Technology Category	Sensors - Flow Meters Sensors - Level Sensors
Applicable Industries	Equipment & Machinery
Applicable Functions	Product Research & Development
Use Cases	Manufacturing Process Simulation Virtual Reality
Challenge	VIKING GmbH, a subsidiary of ANDREAS STIHL AG & Co. KG, is a manufacturer of gardening equipment including lawn mowers. The company is committed to continually improving the performance of its lawn mowers, specifically in terms of mowing performance and noise emission levels. However, the company faced a challenge in understanding the aerodynamics within the deck of the lawnmower. The curved, double-edged blade of the lawnmower induced a highly unsteady airflow, which resulted in vortices that periodically struck the wall of the chute, impacting both the noise emission levels and the catching performance. The fast blade rotation, unsteady pressure, and high fluctuations of the air velocity within the deck created a complex airflow that made traditional development and measurement methods almost impossible. The company needed to find a way to improve the catching performance and simultaneously meet outdoor noise emissions regulations. Read More
About Customer	VIKING GmbH is a 100 percent subsidiary of ANDREAS STIHL AG & Co. KG, based in Austria. The company is an innovative, service-oriented manufacturer of gardening equipment, including lawn mowers, lawn scarifiers, lawn tractors, garden shredders, and tillers. In its lawn mower division, the company is focused on offering the most comfortable and efficient tools possible by continually improving mowing performance and meeting the outdoor noise emissions regulations of their products. VIKING GmbH is committed to innovation and service, continually seeking ways to improve its products and meet the needs of its customers. Read More
Solution	To overcome the challenge, VIKING engineers decided to use ANSYS CFX fluid flow simulation software to simulate the airflow in the lawn mower deck. The goal was to see if numerical simulation could be implemented in the design process. This required confirming the accuracy of results with experimental measurements and verifying the benefits that can be gained from the insight provided with computational fluid dynamics (CFD). The engineers set up the wall, counter rotating wall, and opening boundary conditions in ANSYS CFX-Pre. They then performed URANS simulation with a transient rotor stator model using ANSYS CFX software and performed post-processing in ANSYS CFD-Post. This approach allowed them to compare the computed characteristic parameters of the airflow with measurements in the chute of the lawnmower. Read More Log in to view content
Contents

Technology Category

Sensors - Flow Meters

Sensors - Level Sensors

Applicable Industries

Equipment & Machinery

Applicable Functions

Product Research & Development

Use Cases

Manufacturing Process Simulation

Virtual Reality

Challenge

VIKING GmbH, a subsidiary of ANDREAS STIHL AG & Co. KG, is a manufacturer of gardening equipment including lawn mowers. The company is committed to continually improving the performance of its lawn mowers, specifically in terms of mowing performance and noise emission levels. However, the company faced a challenge in understanding the aerodynamics within the deck of the lawnmower. The curved, double-edged blade of the lawnmower induced a highly unsteady airflow, which resulted in vortices that periodically struck the wall of the chute, impacting both the noise emission levels and the catching performance. The fast blade rotation, unsteady pressure, and high fluctuations of the air velocity within the deck created a complex airflow that made traditional development and measurement methods almost impossible. The company needed to find a way to improve the catching performance and simultaneously meet outdoor noise emissions regulations.

About Customer

VIKING GmbH is a 100 percent subsidiary of ANDREAS STIHL AG & Co. KG, based in Austria. The company is an innovative, service-oriented manufacturer of gardening equipment, including lawn mowers, lawn scarifiers, lawn tractors, garden shredders, and tillers. In its lawn mower division, the company is focused on offering the most comfortable and efficient tools possible by continually improving mowing performance and meeting the outdoor noise emissions regulations of their products. VIKING GmbH is committed to innovation and service, continually seeking ways to improve its products and meet the needs of its customers.

Solution

To overcome the challenge, VIKING engineers decided to use ANSYS CFX fluid flow simulation software to simulate the airflow in the lawn mower deck. The goal was to see if numerical simulation could be implemented in the design process. This required confirming the accuracy of results with experimental measurements and verifying the benefits that can be gained from the insight provided with computational fluid dynamics (CFD). The engineers set up the wall, counter rotating wall, and opening boundary conditions in ANSYS CFX-Pre. They then performed URANS simulation with a transient rotor stator model using ANSYS CFX software and performed post-processing in ANSYS CFD-Post. This approach allowed them to compare the computed characteristic parameters of the airflow with measurements in the chute of the lawnmower.

Impact #1	The use of ANSYS CFX software provided VIKING engineers with a deeper understanding of the aerodynamics within the deck of the lawnmower. They were able to localize and optimize the main vortices, which are a source of sound emissions, by identifying areas of high turbulent fluctuations. They also discovered boundary separation in the lawn mower chute and were able to prevent this separation by filling the separation area. The software also gave them the ability to consider flow within the entire three-dimensional lawnmower and select and evaluate the most important variables that are characteristic for the fluid flow but cannot be measured experimentally due to the rotating blades. This has resulted in improved catching performance and reduced noise emissions, enhancing the overall performance of the lawnmowers.

Impact #1

The use of ANSYS CFX software provided VIKING engineers with a deeper understanding of the aerodynamics within the deck of the lawnmower. They were able to localize and optimize the main vortices, which are a source of sound emissions, by identifying areas of high turbulent fluctuations. They also discovered boundary separation in the lawn mower chute and were able to prevent this separation by filling the separation area. The software also gave them the ability to consider flow within the entire three-dimensional lawnmower and select and evaluate the most important variables that are characteristic for the fluid flow but cannot be measured experimentally due to the rotating blades. This has resulted in improved catching performance and reduced noise emissions, enhancing the overall performance of the lawnmowers.

Benefit #1	Good agreement achieved with velocity measurements in the chute of the mower
Benefit #2	Prevented boundary separation in the lawn mower chute in a second step by filling the separation area
Benefit #3	Optimized the main vortices, a source of sound emissions, by identifying areas of high turbulent fluctuations

Benefit #1

Good agreement achieved with velocity measurements in the chute of the mower

Benefit #2

Prevented boundary separation in the lawn mower chute in a second step by filling the separation area

Benefit #3

Optimized the main vortices, a source of sound emissions, by identifying areas of high turbulent fluctuations

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Overview

Engineering Simulation for Performance and Noise Reduction in Lawn Mowers: A Case Study of VIKING GmbH

Operational Impact

Quantitative Benefit