Is this project an undergraduate, graduate, or faculty project?
Undergraduate
Project Type
individual
Campus
Daytona Beach
Authors' Class Standing
Grayson Hayes, Junior
Lead Presenter's Name
Grayson Hayes
Lead Presenter's College
DB College of Engineering
Faculty Mentor Name
Surabhi Singh
Abstract
This project aims to gauge the effects which asymmetry plays on the aerodynamics of an overexpanded nozzle following separation. Individual nozzles are designed for their ideal conditions, under which a uniform supersonic flow will be produced. One of the main conditions for a nozzle is its design Nozzle Pressure Ratio (NPR). As nozzles stray from their ideal NPR, either above or below, the nozzle flow will become either under- or overexpanded, respectively. Each of these conditions behaves differently. An overexpanded nozzle flow will compress itself to reach equilibrium, resulting in a series of shocks and expansions. An underexpanded nozzle will expand itself to match the pressure which it exits to. This project utilizes computational and experimental methods to gauge the differences in flow separation for overexpanded symmetric and asymmetric nozzles. Z-type Schlieren, a flow visualization technique which captures density gradients within a flow, has been used to capture the flow within an overexpanded symmetric and asymmetric nozzle. Data from this Schlieren has been used to track the initial separation shock in the symmetric nozzle using a Shock Detection Scheme. Computational Fluid Dynamics has been used to provide a computational solution for each nozzle. Results from this study have applications in any vehicle which experiences ambient pressures which differ from their ideal condtion. Overexpansion can result in a thrust differential which can be detrimental to the stability of a vehicle.
Did this research project receive funding support (Spark, SURF, Research Abroad, Student Internal Grants, Collaborative, Climbing, or Ignite Grants) from the Office of Undergraduate Research?
No
Effects of Asymmetry on Flow Separation in Overexpanded Nozzles
This project aims to gauge the effects which asymmetry plays on the aerodynamics of an overexpanded nozzle following separation. Individual nozzles are designed for their ideal conditions, under which a uniform supersonic flow will be produced. One of the main conditions for a nozzle is its design Nozzle Pressure Ratio (NPR). As nozzles stray from their ideal NPR, either above or below, the nozzle flow will become either under- or overexpanded, respectively. Each of these conditions behaves differently. An overexpanded nozzle flow will compress itself to reach equilibrium, resulting in a series of shocks and expansions. An underexpanded nozzle will expand itself to match the pressure which it exits to. This project utilizes computational and experimental methods to gauge the differences in flow separation for overexpanded symmetric and asymmetric nozzles. Z-type Schlieren, a flow visualization technique which captures density gradients within a flow, has been used to capture the flow within an overexpanded symmetric and asymmetric nozzle. Data from this Schlieren has been used to track the initial separation shock in the symmetric nozzle using a Shock Detection Scheme. Computational Fluid Dynamics has been used to provide a computational solution for each nozzle. Results from this study have applications in any vehicle which experiences ambient pressures which differ from their ideal condtion. Overexpansion can result in a thrust differential which can be detrimental to the stability of a vehicle.