Discussion Overview
The discussion revolves around the feasibility of achieving significant thrust with minimal fuel consumption using high-pressure gas ejection, specifically in the context of lifting a human or lightweight craft. Participants explore the implications of pressure, nozzle size, and mass flow rate in this scenario.
Discussion Character
- Exploratory, Technical explanation, Debate/contested
Main Points Raised
- One participant suggests that a force of 1500 N and a velocity of 200 m/s could be achieved with a mass flow rate of 0.0007 kg/s using a pressure of 15 MPa.
- Concerns are raised about the practicality of using a 1 cm² nozzle at 15.1 MPa pressure.
- Questions are posed regarding the calculation of effective velocity when releasing gas from a high-pressure reservoir without combustion.
- Another participant points out that the initial assumptions may be flawed as the tool used for calculations assumes combustion rather than simply releasing gas from a reservoir.
- There is confusion about why the mass loss rate appears to be negative when increasing pressure.
- The original poster expresses uncertainty about the calculations and suggests that a polynomial approach might yield better results.
Areas of Agreement / Disagreement
Participants appear to have differing views on the assumptions made regarding the calculations, particularly concerning the role of combustion versus high-pressure gas ejection. The discussion remains unresolved as participants have not reached a consensus.
Contextual Notes
Limitations include potential misunderstandings of the assumptions behind the calculations, particularly regarding the nature of the gas ejection process and the implications of pressure on mass flow rate.