Using simulation tools for improvement of small home appliances design

B S H H O M E A P P L I A N C E S G R O U P

Using simulation tools for improvement of small home

appliances design

Ansys Convergence Conference

2016

25th May 2016

dr. Henri Orbanić, Marko Žilnik

B S H H O M E A P P L I A N C E S G R O U P Using simulation tools for improvement of small home appliances design | 25th May 2016 | Slide: 2

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About BSH HOME APPLIANCE GROUP

Founded in 1967 as a joint venture between

Siemens AG and Robert Bosch GmbH

Since the beginning of 2015 BSH fully belongs to the

Bosch Group

Market leader in Europe, No. 2 in the world

Product portfolio: all modern home appliances

Employees worldwide: 56,500

Around 3,500 R&D specialists in BSH’s international

production and development network

BSH Hausgeräte GmbH

Founded in 1967

Robert Bosch

GmbH

100%


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BSH’s product portfolio covers the entire spectrum for daily life


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Short presentation of BSH Hišni aparati d.o.o Nazarje, Slovenia

~1200 employees

~7 million appliances produced

per year

Two branches:

Food preparation

Beverages preparation


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Products developed and produced in Nazarje – Food preparation

Food processors Kitchen machines Stick mixers

Hand blenders

Blenders

Juicers Citrus press Choppers Meat grinders


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Using ANSYS in Food preparation department

Personnel: two part-time simulation engineers

Hardware:

– Two simulation workstations Dell T7910 with 16-cores each

Software:

– Structural analysis:

– ANSYS Mechanical (Static structural, Transient structural, Modal, Thermal)

– ANSYS Explicit STR (Impact testing)

– CFD analysis:

– ANSYS Fluent


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Structural analysis simulation in

BSH Hišni aparati d.o.o. Nazarje


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Stick mixer drop test

The user has to be prevented from touching live electronics if the appliance is

damaged after it is accidentally dropped on the floor.

Thus the appliance housing must not open if it falls from the kitchen counter.

One of our stick mixers had problems with this test.

The goal was to have a solution which would be cheap and easy to implement as the

modifications to the moulding tools are expensive.

High speed camera – 1900 fps

t=0 t=2,63 ms t=4,74 ms


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Simulation setup

Cross section

Mass to

simulate motor

and electronics

Gravity +

initial

velocity

Fixed

floor

Housing

material: ABS


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The existing situation

The simulation was performed in ANSYS Explicit STR.

First the simulation of the existing situation was performed.

The simulation showed similar opening of housing as in real drop. Thus we could proceed to

modifying of housing design.


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Solution

After the modification of locks the housing did not open anymore


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Drop test of packed appliances Software: Before - outsourcing LS-DYNA,

Now – ANSYS Explicit STR

Lateral drop test from the height of 50 cm,

v0 = 3,13 m/s, angle to the ground 10°

10°


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Drop test - plastic strain analysis


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Bosch MUM5 blender locking mechanism structural problem

Problem: the geometry and material was changed. During usage the locking mechanism

broke.

The problem was solved by the design change .


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CFD simulation in BSH Hišni aparati

d.o.o. Nazarje


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Stick mixer performance analysis

water

level

pressure

outlet

water

rotation zone

air


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Simulation parameters

Two phase water-air VOF model

High rotational velocity ~ 12000 rpm turbulence

Transient formulation


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Mixing analysis

Inserting tracer liquid and observing the uniformity of mixing


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Bosch MCM6 food processor blender attachment


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Simulation parameters

Two phase water-air VOF model

0.75 l of water was simulated

Rotational velocity – 6000 to 12000 rpm,

Transient formulation


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Kneading bread dough

Bread dough – mainly mixture of wheat flower and water.

Depending on the flower-water ratio, the dough can be a

dry plastic ball or a soft sticky mass.

Points of interest:

– obtaining load regime on the machine,

– studying the kneading process – kneading efficiency.


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THANK YOU FOR YOUR ATTENTION

Using simulation tools for improvement of small home appliances design

Engineering