Thomson's Turbine — Flow Classification Thomson's turbine is classified as which type of reaction turbine based on flow direction?

Introduction:
Reaction turbines are categorized by how water moves through the runner: inward radial, outward radial, axial, or mixed flow. Knowing which historical designs belong to each class helps in understanding their geometry and performance envelopes.

Given Data / Assumptions:

• Thomson's turbine is a classic reaction-type machine.
• Classification depends on absolute flow direction through the runner.

Concept / Approach:
In an inward-flow reaction turbine, water enters near the periphery and moves radially inward while doing work on the runner. Thomson's turbine belongs to this inward-flow category, distinct from Fourneyron's outward-flow turbine and Kaplan's axial-flow turbine. Francis turbines later evolved as mixed/inward-flow variants with improved efficiency.

Step-by-Step Solution:
Identify historical prototypes: Fourneyron (outward), Thomson (inward), Kaplan (axial).Match Thomson's runner passages with inward radial motion.Therefore, classify it as an inward-flow reaction turbine.

Verification / Alternative check:
Textbook schematics depict Thomson's runner passages directing water inward toward the center.

Why Other Options Are Wrong:
axial flow: corresponds to Kaplan/propeller machines.outward flow: corresponds to Fourneyron's design.mixed flow: used for Francis; not the original Thomson layout.

Common Pitfalls:
Confusing historical names: Fourneyron = outward; Thomson = inward; Kaplan = axial.

Final Answer:
an inward flow