Simple Brayton (gas turbine) cycle – determinants of work ratio In a simple, open Brayton cycle without regeneration or intercooling, the work ratio (net work / turbine work) primarily depends on which of the following parameters?

Introduction / Context:
The work ratio measures how much of the turbine's output is available as net work after driving the compressor. It is a key performance indicator for gas turbines and is sensitive to temperature limits and pressure ratio choices.

Given Data / Assumptions:

• Simple Brayton cycle: compressor → combustor → turbine.
• Fixed component efficiencies for qualitative discussion.
• No regeneration, intercooling, or reheat.

Concept / Approach:

Turbine work and compressor work scale with absolute temperature levels. Increasing turbine inlet temperature (maximum cycle temperature) raises turbine work more than compressor work, improving work ratio. Lowering minimum cycle temperature (compressor inlet) increases density and reduces compressor work per unit mass flow, improving the ratio. Pressure ratio alters both compressor and turbine specific works; there exists an optimum pressure ratio for peak specific work and efficiency at given Tmax and Tmin. Therefore, all listed parameters influence the work ratio significantly.

Step-by-Step Solution:

Verification / Alternative check:

T–s diagrams show larger turbine area minus compressor area as Tmax increases or Tmin decreases; parametric studies confirm sensitivity to pressure ratio as well.

Why Other Options Are Wrong:

Single-parameter claims ignore the coupled dependence of Brayton-cycle work terms on both temperature limits and pressure ratio.

Common Pitfalls:

Focusing only on pressure ratio while neglecting inlet cooling or turbine inlet temperature constraints imposed by materials.

Final Answer:

all of these