Close Circuit Wind Tunnel

About Close Circuit Wind Tunnel

Overview

High-performance closed-circuit wind tunnels engineered for precision aerodynamic testing and energy-efficient operation. Built with robust steel construction, these systems offer complete design flexibility to accommodate space constraints, structural limitations, and specialized research requirements.

Designed primarily as single-return, horizontal circuits, each system delivers exceptionally stable, low-turbulence airflow suitable for advanced R&D and academic applications.

 Key Advantages

• Ultra-Low Turbulence: Typically, < 0.10% across full speed range
• Energy Efficient: Lower power requirement vs. open-circuit tunnels
• Stable Flow Conditions: Isolated from ambient lab disturbances
• Low Noise Operation
• Clean Airflow: Dust and particulates contained within the circuit
• Enhanced Equipment Safety: Reduced risk to fan system

Technical Datasheet (Typical Ranges)

Performance

• Airspeed Range: 5 to 150 m/s (customizable based on design)
• Turbulence Intensity: < 0.10%
• Flow Uniformity: 0.5% across test section

Circuit Configuration

• Type: Single-return (standard), multi-return/custom available
• Orientation: Horizontal (vertical/custom layouts optional)
• Construction: Heavy-duty steel fabrication

Test Section

• Size Range: 0.3 m 0.3 m to 3 m 3 m (customizable)
• Length: 1 m to 10 m
• Access: Modular panels, optical windows, instrumentation ports

Flow Conditioning

• Contraction Section:
• Ratio: 6:1 to 12:1 (typical)
• Profile: 5th- or 9th-order polynomial contour for smooth acceleration
• Settling Chamber: Multi-stage flow straightening and screening
• Diffusers & Corners: Optimized for minimal pressure loss

 Design Considerations

Advantages vs Open Circuit

• Lower operating power for equivalent speeds
• Controlled environment for particulate or sensitive testing
• Minimal external airflow interference
• Reduced acoustic emissions

Limitations

• Higher capital cost (~23 for similar test section size)
• Larger installation footprint
• Heat buildup during extended operation
• Not ideal for combustion or exhaust-intensive testing

Customization Options

• Low-height or space-constrained layouts
• Integration around building columns/structures
• Thermal control systems (cooling/heat exchangers)
• Advanced instrumentation & automation
• Specialized test sections (aeroacoustics, automotive, UAV, etc.)

Applications

• Aerospace and automotive aerodynamics
• High-precision research and calibration
• Environmental and flow physics studies
• Academic laboratories and national research centres