Integrated Rocket Ramjet

To design an integrated rocket ramjet. The emphasis on designing a unique nosecone to function dually as an inlet for the ramjet, as well as a removable diaphragm between the ramjet engine and the solid rocket propellant.

Background
A ramjet is a type of engine used for supersonic flight. It operates at speeds around Mach 3 but cannot function at speeds much lower than Mach 1.5. Because of this, ramjet engines are typically brought to an ideal speed before activating. Currently this is done in two ways; first being by a booster rocket that detaches after usage, and second by carrying the ramjet engine on a jet plane and dropping it when the engine ignites. The goal for this project is to develop a third way for ramjet flight, utilizing a solid rocket combustion chamber and a nosecone that can function as an inlet at high speeds.

Deliverables
The deliverables for this project include; a detailed design for an adjustable nosecone and diaphragm that utilizes aerodynamics, a quarter cut out model showing the functionality of the integrated ramjet, and a basic model of the rocket that can be used for simplified testing of the nosecone, diaphragm, and other assemblies/components.

Project Learning
Most of the project learning for the integrated rocket ramjet revolved around ramjets and their functionality, as well as solid rockets and how to design them. For this design, in order to get the ramjet to speed a solid rocket will be attached to the ramjet engine. Once the propellant is burned, the rocket will function as the combustion chamber for the ramjet. To make this design possible, research had to be done on both rocket propellants and ramjet engines.

The image on the left below shows different grain geometries for solid rocket propellant. This was useful because it helped us decide which geometry would give us the best thrust pattern to obtain the proper transition speed. We ultimately decided to go with #2, this option provided the rocket with consistent thrust which allows for easier calculations and design.

Along with propellant research we found information on the functionality of the ramjet. Below on the right is a basic image on how a ramjet operates. Using this information we were able to brainstorm ideas on how to create a moving nosecone and where to store the liquid fuel for the ramjet part of flight. We found the best place to store the liquid fuel would be in the extra space by the diffuser (the yellow section of the image).

Concept and Design
To get the Ramjet to its ideal flight path, solid rocket propellant is stored in the ramjet’s combustion chamber and functions initially as a rocket booster. During this stage the nose cone to the ramjet engine will remain shut and a diaphragm will be in place to block any solid propellant from getting into the rest of the engine (this can be seen in the first image below).

Once the solid propellant is burnt, the nose cone and diaphragm open up allowing the ramjet to begin operation. This part of the design is important because it allows for the whole body to become the ramjet, and does not require the rocket portion to drop off. Instead the space where the solid rocket propellant was stored is now the combustion chamber for the ramjet. The ramjet then takes over for the rest of the flight, operating at its design conditions (this can be seen in the second image below).

Document Archive
[[Media: Meeting_Minutes2.0.pdf|Meeting Minutes]]