Tandem rotor configurations in axial flow compressors offer key advantages, including higher pressure rise, superior aerodynamic efficiency, wider stall margins, and lower complexity. They also enable greater compactness and lighter weight—critical attributes for demanding applications. These strengths position tandem-bladed compressors as an ideal option for aerospace uses, where performance and reliability are paramount. As compressor technology advances, tandem designs promise enhanced efficiency, flexibility, and a pivotal role in next-generation propulsion systems and industrial equipment.
Rig specifications:
Casing dia = 400 mm
Hub dia = 200 mm
Max speed = 2800 rpm, 15kW
Mass flow rate 3.75 kg/s
The existing facility is capable of exploring various activities like:
1. For testing of Industrial fans, ventilation fans, Land-based power plant compressors and fans, and Aircraft axial flow compressors for low-speed testing (HP Compressor), small-engine compressor tests.
2. Interchangeable rotor-stator disk capabilities as per the requirements of new designs.
3. Adaptability for PIV and hot-wire measurements, supporting detailed fundamental and applied research.
4. Flow characterization for axial flow compressor/fan stage under various inflow conditions.
5. Active, Passive flow control study for operating range and/or performance improvement
Contra Rotating Axial- Centrifugal Compressor Test Rig
The Contra-rotating axial-centrifugal compressor (CRAC) configuration combines a contra-rotating axial compressor stage with a back-end centrifugal compressor stage driven on twin spools/shafts. The contra-rotating axial stage with low-aspect-ratio blading increases stage loading, allowing for fewer axial stages than conventional designs to achieve the same pressure rise. The combined axial–centrifugal layout exploits the advantages of both types: high flow capacity from the axial stage and high head from the centrifugal stage. A radial-to-axial turning annular passage and curved discharge diffuser (axial or slightly inclined, about 10–15°) minimize outer diameter and axial length, giving a compact, lightweight module with fewer parts. This is Patented technology (US Patent No. 12,188,406 Grant Date: January 7, 2025) and the only facility in the World. We are actively seeking commercialization and/or Licensing Opportunities.
Rig specifications:
Casing dia = 300 mm
Hub dia = 100 mm
Max speed = 2800 rpm and 3600 rpm , 11kW & 22kW
Mass flow rate 2 kg/s
The existing facility is capable of exploring various activities like:
1. For testing of Industrial fans, ventilation fans, Land-based power plant compressors, Aeroengine compressors, and small-engine compressor tests.
2. Adaptability for PIV and hot-wire measurements, supporting detailed fundamental and applied research.
3. Flow characterization for axial flow compressor/fan stage under various inflow conditions.
4. Active, Passive flow control study for operating range and/or performance improvement
5. Aircraft/Helicopter/UAV intake testing.
Annular Sector Cascade Tunnel Facility
The Annular Sector Cascade Tunnel at IIT Kharagpur is a premier experimental facility. Unlike conventional linear cascades, this tunnel simulates the three-dimensional flow physics of actual turbomachines by accounting for radial pressure gradients and centrifugal effects.It is primarily used to evaluate the aerodynamic performance of axial compressor and turbine blade rows under realistic subsonic and transonic flow conditions as well as Reynolds number mimic. The facility enables the detailed study of complex phenomena such as secondary flow structures, tip leakage vortices, and blade-to-blade interactions. Equipped with high-precision instrumentation, including multi-hole pressure probes and non-intrusive Particle Image Velocimetry (PIV), it provides high-resolution flow field data. These experimental results are vital for validating advanced Computational Fluid Dynamics (CFD) codes and optimizing blade geometries. Ultimately, the tunnel serves as a cornerstone for indigenous research in gas turbine technology, contributing significantly to India's aerospace and defense propulsion programs.
Rig specifications:
Max blower Volume flow rate = 5 m3/s
Blower Static Pressure rise = 19.6 kPa, 155kW
Test Mach number of 0.3, which can be extended up to Mach 0.7, Reynolds number in the range of 10^5
The Annular Sector Cascade Tunnel is designed for operational flexibility, utilizing interchangeable nozzles to adapt to specific flow conditions. This facility provides a sophisticated platform for the following research and industrial applications:
Aerodynamic and Flow Physics Studies
Three-Dimensional Flow Analysis: Investigation of 3D secondary flow formations using actual blade and vane geometries, specifically accounting for the radial pressure gradients found in real-world turbomachinery.
Geometric Parametric Studies:
Evaluation of how specific design changes influence flow physics, including:
Stacking definitions and the effects of lean and sweep angles.
Leading-edge contouring strategies.
Axisymmetric and non-axisymmetric endwall contouring to manage secondary losses.
Component Interaction and Loss Mitigation Rotor-Stator Interactions:
a. Analysis of periodically unsteady flow interactions between rotating and stationary components at engine-representative Reynolds and Mach numbers.
b. Investigation of advanced tip modification techniques aimed at reducing tip leakage losses, a critical factor in enhancing stage efficiency.
Thermal Management and Aero-Mechanics:
a. Study of the impact of upstream film cooling on contoured endwalls and the performance of internal blade cooling technologies under engine-representative conditions.
b. Specialized testing for structural-aerodynamic phenomena, such as flutter, to ensure blade stability and longevity.
High Speed Pressure Probe Calibration Facility
The High-Speed Multi-Hole Pressure Probe Calibration Facility is a specialized laboratory designed for the precise aerodynamic characterization of flow sensors. It features a high-speed jet capable of reaching transonic Mach numbers, providing a controlled environment for calibrating 3-hole, 5-hole, and 7-hole probes. The facility uses an automated multi-axis indexing system to vary the probe’s pitch and yaw angles with high angular resolution. This setup enables researchers to map pressure coefficients across a wide range of flow angles and Mach numbers, ensuring accurate data in complex 3D flow fields. Advanced data acquisition systems integrate pressure scanners and temperature sensors to account for compressibility effects during calibration. The resulting calibration maps are essential for experimental research in the Annular Sector Cascade Tunnel and other high-speed turbomachinery rigs. By providing high-fidelity measurements of total pressure, static pressure, and velocity vectors, the facility supports the development of indigenous aerospace propulsion systems. Ultimately, it serves as a critical resource for validating CFD models and improving the aerodynamic performance of gas turbine components.
Rig specifications:
Mach number - 0.2 to 0.7
Angular Range
Pitch direction: -45° to +45°
Yaw direction: -180° to +180°
Step Size (both directions): Minimum step size: 1°
Yaw control:
Stepper motor - Nema 23 & NEMA34 with 2.5 Nm and 6.8Nm torque
Power Supply – 48V
Microstepping Drive – BH SMART - 4.5A
Gear Ratio – 1:1.8
Low Speed Pressure Probe Calibration Facility
The Low-Speed Multi-Hole Pressure Probe Calibration Facility is a specialized experimental rig within the Turbomachines Research Lab, dedicated to the high-precision characterization of aerodynamic sensors. It is used to calibrate 3-hole, 4-hole, 5-hole, and 7-hole probes essential for measuring 3D velocity vectors and pressure fields. The facility features an automated two-axis angular traverse mechanism that precisely controls the probe's pitch and yaw angles. The system achieves an angular resolution of approximately 0.5°, supporting pitch ranges as wide as $\pm 70^\circ$ for non-nulling calibration. It typically operates at subsonic speeds (e.g., 35 m/s), providing a stable, low-turbulence environment for calculating Reynolds-independent coefficients. High-fidelity calibration maps generated here allow for the extraction of total pressure, static pressure, and flow angles from raw probe data. These calibrations are crucial for experimental studies on complex phenomena, such as secondary flows and tip leakage, in axial compressors. The facility serves as a cornerstone for validating advanced Computational Fluid Dynamics (CFD) codes and supporting indigenous aerospace propulsion programs.
Rig specifications:
Mach number - 0.2 to 0.7
Angular Range
Pitch direction: -45° to +45°
Yaw direction: -180° to +180°
Step Size (both directions): Minimum step size: 1°
Yaw control:
Stepper motor - NEMA 23 & NEMA34 with 2.5 Nm and 6.8Nm torque
Power Supply – 48V
Microstepping Drive – BH SMART - 4.5A
Gear Ratio – 1:1.8
Linear cascade Tunnel Facility
The Low Speed Linear Cascade Tunnel at IIT Kharagpur is a vital experimental facility designed to evaluate the aerodynamic performance of 2D blade profiles in a controlled, subsonic environment. Simplifying complex turbomachinery stages into a linear arrangement allows for high-resolution studies of fundamental flow physics and loss mechanisms.
The research capabilities of this facility are categorized as follows:
1.The rig is used to quantify the variation in static pressure coefficient distribution around the airfoil surfaces as a function of the incidence angle, identifying regions of flow acceleration and potential separation.
2.
It facilitates the analysis of secondary flow structures (such as passage and horseshoe vortices) in the absence of radial pressure gradients, allowing for the isolation of purely three-dimensional endwall effects.
3.
The facility enables a detailed breakdown of total pressure losses through the flow passage, losses arising from boundary layer growth and wake mixing, Aerodynamic penalties associated with flow through the tip-gap clearance, and Viscous losses generated near the hub/shroud and within vortex structures.
4.The facility investigates the impact of blade design variables on loss generation, specifically focusing on Variations in stagger angle and space-chord ratio, the efficacy of leading-edge modifications and axisymmetric/non-axisymmetric endwall contouring in mitigating secondary flows.
5.The rig allows for the systematic variation of upstream boundary conditions to observe their effects on stage performance, like Reynolds number, free-stream turbulence, Inlet Mach number, and upstream wake impingement.
6.The tunnel is equipped to perform heat transfer studies, evaluating the effectiveness of internal blade cooling and endwall film cooling configurations under engine-representative conditions.
7.It provides a platform to investigate aero-elastic behavior (such as flutter and forced response) and aero-thermal coupling across a broad range of operational flow regimes.
Rig specifications:
Max blower Volume flow rate = 1.67 m3/s
Blower Static Pressure rise = 19.6 kPa, 155kW
Test section 100 mm *500 mm
Test Mach number of 0.3, which can be extended up to Mach 0.7, Reynolds number in the range of 10^5
Characterisation of Boundary Layer Over Blade Surfaces
The Boundary Layer Characterization Facility is a specialized experimental setup designed to investigate the fundamental fluid mechanics of boundary layer (BL) development under engine-representative conditions. The rig utilizes a flat plate-based configuration where a contoured upper wall is employed to impose specific pressure gradients—including Zero (ZPG), Favorable (FPG), and Adverse (APG)—simulating the flow environment typically found in modern Low-Pressure (LP) turbine passages.
The facility is highly versatile, allowing for the systematic characterization of the BL with variations in upstream turbulence intensity, Reynolds number, and angle of incidence. Furthermore, the rig enables researchers to study the impact of passage area (solidity) and surface roughness on BL transition and separation. Beyond standard characterization, the facility supports advanced research into the morphing of blade profiles and various flow control strategies. By providing high-fidelity data on BL behavior under these diverse parameters, the facility serves as a critical tool for optimizing the aerodynamic efficiency and thermal management of next-generation turbomachinery components.
The Gas Turbine Film and Sweeping Jet Cooling Testing Facility at IIT Kharagpur is an advanced experimental rig designed to evaluate high-efficiency cooling strategies under representative engine conditions. The facility utilizes a flat plate configuration where a favorable pressure gradient (FPG) is superimposed to simulate the accelerating flow fields of turbine passages.
The rig operates with atmospheric air inflow, using liquid nitrogen to establish the necessary temperature difference to achieve realistic density ratios between coolant and mainstream flow. It allows for comprehensive testing across a range of upstream turbulence intensities, Reynolds numbers, and various angles of incidence. The facility supports detailed study of convective heat transfer and aerodynamics for both internal passage and external film cooling. It is used for the performance assessment of novel cooling technologies, including various sweeping jet configurations and the cooling of electronic equipment. The rig facilitates material performance testing and provides high-fidelity experimental data acquisition using modern state-of-the-art instrumentation techniques, such as Hot-wire Anemometry, PIV, Infrared Thermography, and pressure scanners. The experimental data is also essential for the validation of CFD codes. Researchers utilize the facility to investigate the efficacy of different cooling mechanisms, various configurations, and innovative designs to mitigate thermal stresses in Gas turbine components, ensuring the feasibility of safe operation.
