Centrifugal Fan Heat Sink Layout to Suppress Air Recirculation
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Solution Overview
Problem
Conventional cooling devices using centrifugal fans with short axial lengths face reduced cooling capacity due to air circulation gaps, making it difficult to select an appropriate fan size for each heat sink.
Innovation Solution
A cooling device design with protruding parts on the flat plate-shaped members to minimize gaps between the centrifugal fan and the heat sink, ensuring air flows efficiently through the air flow path by narrowing the gaps and improving airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a centrifugal fan with short axial length is used to miniaturize the cooling device, then the device size is reduced, but a large gap occurs between the fan and the flat plate-shaped member causing air to circulate inside the heat sink and reducing cooling capacity
Solution Approach 1:
A guide member is introduced as an intermediary component between the centrifugal fan and the flat plate-shaped member. The guide member extends from the flat plate-shaped member toward the centrifugal fan, with its tip positioned within the air flow from the fan outlet. This intermediary structure directs the air flow along the heat radiation fins and prevents air from entering the gap and circulating inside the heat sink, thereby resolving the contradiction between miniaturization and cooling capacity.
2Reliability
If the centrifugal fan size is matched to the heat sink size to avoid gaps, then cooling capacity is maintained, but it becomes very difficult to select an appropriate fan size for each heat sink
Solution Approach 1:
The cooling device is segmented into modular components: a standardized centrifugal fan unit and a heat sink assembly with an integrated guide member. The guide member is designed as a separate component that can be attached to the heat sink. This segmentation allows the centrifugal fan to be selected independently based on cooling requirements without being constrained by heat sink dimensions, while the guide member adapts to ensure proper air flow guidance regardless of the specific fan-heat sink pairing.
3Device complexity
If air enters the gap between the centrifugal fan and the flat plate-shaped member, then air circulates inside the heat sink and the amount of air flowing through the flow path decreases
Solution Approach 1:
The guide member acts as an intermediary that intercepts air before it can enter the harmful gap between the centrifugal fan and the flat plate-shaped member. By positioning the guide member's tip within the fan's air flow outlet, it captures and redirects the air along the intended flow path through the heat radiation fins, preventing the air from deviating into the gap and circulating uselessly inside the heat sink.
Solution Approach 2:
The harmful air circulation path is effectively extracted or removed from the system by the guide member. The guide member creates a physical barrier that separates the useful air flow (through the heat radiation fins) from the harmful air circulation (inside the heat sink via the gap), forcing all air to follow the intended cooling path and eliminating the parasitic circulation loop.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances cooling capacity and facilitates easy selection of centrifugal fans by reducing air circulation within the device, even with short axial length fans, while maintaining efficient airflow.
Implementation Method 1
a centrifugal fan having an inlet as an opening and an outlet configured to be open in a direction intersecting an opening direction of the inlet
Implementation Method 2
air is taken into the inside of the centrifugal fan from the inlet and is discharged from the outlet. The cooling device is cooled by the air discharged from the outlet of the centrifugal fan flowing through the flow path
Implementation Method 3
a heat sink that dissipates heat generated by a circuit part
Implementation Method 4
the air discharged from the outlet of the centrifugal fan flowing through the flow path formed by the heat radiation fin
Data Source
AI summary
A cooling device includes an upper flat plate-shaped member and a lower flat plate-shaped member disposed with a predetermined interval therebetween, a heat radiation fin configured to extend from the upper flat plate-shaped member toward the lower flat plate-shaped member and to form a flow path through which air flows between the upper flat plate-shaped member and the lower flat plate-shaped member, and a centrifugal fan having an inlet as an opening and an outlet configured to be open in a direction intersecting an opening direction of the inlet, wherein the centrifugal fan is disposed at a position separated from the upper flat plate-shaped member by a predetermined interval so that the outlet is open toward the flow path, and a protruding part that protrudes toward the centrifugal fan is provided on the upper flat plate-shaped member.