Satellite Propulsion Research

Research Title

Optimization of Compressible Flow Expansion in Micro-Scale Thruster Nozzles for CubeSat Propulsion

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Why Micro-Propulsion Matters for CubeSats

The rapid growth of small satellites and CubeSats has transformed space missions by enabling low-cost Earth observation, communication, and scientific exploration. However, these missions demand highly compact, lightweight, and precise propulsion systems for orbit correction, attitude control, and formation flying.

 

Micro-scale thrusters are essential for meeting these requirements, but their performance is often limited by complex compressible flow phenomena that arise at very small scales. Understanding and controlling these flow behaviors is critical for improving thrust efficiency and mission reliability.

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Research Objective

The goal of this research is to optimize the flow expansion process in micro-scale thruster nozzles used for CubeSat propulsion.

We aim to address key questions such as:

• How does compressible flow expand within confined micro-nozzle geometries?

• What role do shocks and flow instabilities play at high expansion ratios?

• How can nozzle geometry and operating conditions be optimized for maximum efficiency?

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Challenges in Micro-Scale Compressible Flow

Unlike conventional rocket nozzles, micro-thruster nozzles operate under:

• Extremely small characteristic dimensions

• High pressure and temperature gradients

• Strong compressibility effects

• Shock formation within limited expansion lengths

These factors make analytical solutions insufficient, requiring high-fidelity numerical simulations to capture real flow behavior.

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Research Methodology and Simulation Approach

This study employs Computational Fluid Dynamics (CFD) using ANSYS Fluent to perform a detailed analysis of micro-thruster nozzle performance.

Key aspects of the methodology include:

• Modeling compressible, high-speed flow through converging–diverging micro-nozzles

• Simulation of both steady-state and transient flow conditions

• Investigation of varying:

  • Inlet pressure and temperature

  • Throat diameter and diverging angle

  • Propellant properties and gas models

This approach allows us to identify optimal operating and design conditions for micro-thruster systems.

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Flow Analysis and Performance Metrics

Post-processing and analysis focus on:

• Velocity and pressure contours

• Mach number evolution along the nozzle

• Temperature distribution and thermal gradients

• Shock formation and shock–boundary layer interactions

• Expansion efficiency and thrust-related performance metrics

These insights help quantify how effectively the nozzle converts thermal energy into directed thrust.

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Significance and Impact

The outcomes of this research will:

• Improve thrust efficiency and controllability of CubeSat propulsion systems

• Support the design of reliable micro-thrusters for long-duration missions

• Provide deeper understanding of high-speed compressible flow in micro-scale geometries

• Contribute to the development of scalable propulsion technologies for future small satellite platforms

This work bridges fundamental fluid dynamics with practical spacecraft propulsion design.

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Opportunities for Researchers and Collaboration

We invite researchers and students interested in:

• Satellite propulsion and space systems

• Compressible flow and shock dynamics

• Micro-scale fluid mechanics

• CFD modeling and high-speed flow simulation

By joining this research effort, collaborators can contribute to next-generation space propulsion technologies that enable advanced CubeSat missions and expand access to space.