Numerical Simulation on the Influence of Injection Location, Injection Angle, and Divergence Half Angle on SITVC Nozzle Flow Field

H R Noaman,Elsayed Khalil,Hai Bin Tang

doi:10.1155/2019/7392497

H R Noaman, Elsayed Khalil + Show 1 more

Open Access

https://doi.org/10.1155/2019/7392497

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Abstract

A numerical study has been performed to characterize the nozzle flow field of secondary injection thrust vector control (SITVC) and to estimate the performance parameters of SITVC. After validating the CFD turbulence models with an experimental data, a numerical simulation has been conducted in order to investigate the influence of changing the injection location, the injection angle, and the primary nozzle divergence half angle on the SITVC nozzle flow field structure and on the SITVC performance parameters. The secondary mass flow rate was kept constant for all cases during the simulation. The results showed that downstream injection near the nozzle exit Mp=2.75 increases the high-pressure zone upstream the injection leading to an increase in the side force; also, the higher divergence half angle 15° slightly increases the side force and it provides a wide range of deflection without shock impingement on the opposite wall becoming more effective for SITVC. The injection angle in the upstream direction 135° increases the side force, and by decreasing the injection angle to downstream direction 45°, the side force decreases. However, the SITVC performance parameters and the flow field structure are more influenced by the injection location and the primary nozzle divergence half angle while being less influenced by the injection angle.

Highlights

Thrust vector control (TVC) is a way that controls the thrust by deflecting the main flow of a rocket motor or jet engine from the main axis to generate a specified force on the desired axis
For a constant secondary mass flow rate influence of the injection location, the injection angle and primary nozzle divergence half angle on the nozzle flow field structure will be discussed in the following part
The secondary injection thrust vector control (SITVC) creates a complex flow field in the nozzle divergent part; Figure 11 illustrates the main components of the SITVC flow field

Summary

Introduction

Thrust vector control (TVC) is a way that controls the thrust by deflecting the main flow of a rocket motor or jet engine from the main axis to generate a specified force on the desired axis. Thrust vector control greatly enhances maneuverability, especially at low velocities or high angles of attack where conventional aerodynamic control surfaces are not effective. The thrust can be controlled mechanically by using flex joints, hinged nozzles, jetavators, and jet vanes/tabs or by fluidic thrust vector (FTV) control. In contrast to the mechanical systems that need actuators to move the mechanical parts leading to complex design and weight penalty, fluidic thrust vector control is a technology with less weight, faster dynamic response, and no mechanical movable parts and is controlled by flow regulations, which decreases the axial thrust losses during a change in the direction of the thrust [1, 2]. There are different techniques of fluidic thrust vector control such as secondary injection thrust vector control (SITVC) or shock vector control (SVC), counter flow, Coanda effect, and throat skewing [3, 4]

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