Technical Report

Technical Information

University of Greater Manchester: Findings To Date

KRISHAN JONES 27/5/2025

This Project has been submitted in part fulfilment of the requirements LAID OUT BY THE CLIENT FOR THE CLEVER CENTRE. ALL INFORMATION IS ONLY TO BE DISTRIBUTED TO ITS INTENDED RECIPIENT.

Aims:

This report is a collation of all data and findings for The Clever Centre project to date. The logical timeline of the project has been recounted and reflective comments made upon each step.

INFORMATION

The primary aim of this project was to provide empirical and simulated evidence to prove the function of the client’s designs. This encompassed a full parameterised CAD design of multiple of the client’s geometries within Dassault Systems’ SolidWorks package, followed by CFD simulation of the flow through each.

CFD Results showed changes in water pressure across boundaries, and as such an empirical approach could be taken to calculate the mass of dissolved air that was removed from the system through cavitation.

The project also aimed to accurately model the flow paths of air bubbles within the system. Overall flow was calculated correctly, but specific flow patterns were deemed too time consuming to simulate for the data that could be garnered from them.

Multiphase CFD simulations were designed to accurately emulate the appropriate operating conditions of each geometry. A low-pressure column was observed central to the geometries. This low-pressure volume can be seen in the original study provided by the client and is an accurate approximation of bubble pathing.

The report closes by advising that the Centre for Advanced Manufacturing has provided the extent of its services to the client and suggests that the client moves to production. The CfAM has approached partners for mass scale production options and will advise the client through the production prototype phase. / The CfAM will advise the client through the production prototype phase and will assist with locating a production partner should the client require.

GEOMETRY

CLIENT REQUIREMENTS IN CAD

The original CAD provided by the client was reverse engineered and cleaned. Parametric CAD models were designed to client specification, with baked in geometries that accommodate changes further on in the development cycle.

Figure 1 – Original CAD

Figure 2 – Redesigned CAD with smoothed spout

Changes implemented from Figure 1 to Figure 2 include a redesign of the main spout geometry. This was done to lower internal flow volume face count and simplify simulation.

Figure 3 – Split design with cavity for brazing.

Early manufacturing concepts included splitting the model along its XY plane. The two halves were designed with a cavity to reduce potential penetration into the flow volume through capillary action.

Figure 3 shows a close-up view of the split.

This part of the project has been paused until manufacture processes can be finalised.

Figure 4 – 90-degree inlet

To increase the flow velocity into the chamber the client asked for the inlet to be tangential to the vortex direction. Figure 4 shows the first interpretation of the design. Figure 5 through Figure 10 shows the development of a planar inlet that was tangential to the flow direction, but within the plan profile of the main body.

Figure 5 – Tangential inlet

Figure 6 – The perceived flow through this geometry was much improved

Figure 7 – The client wished for the inlet to be closer to the edge of the bowl

Figure 8 – V2 with inlet closer to the edge of the bowl, but within the plan profile.

Figure 9 – V3 with inlet outside of profile

Figure 10 – Client wanted inlet to be brought back into the profile

Figure 11 – V4 with gradient inlet

Figure 12 – Client asked for a straight inlet pipe

Figure 13 – Finalised geometry

One of the key design requirements set by the client was a large, flat side wall in the main body that would allow a third party to split the model cleanly in half. Figure 14 shows the finalised design with a clean external wall with plenty of space to split the model.

EQUATION DRIVEN DESIGN

Figure 14 – Finalised

Figure 15 – Final iteration

The client was happy with the design. This version was then parameterised so that different configurations could be iterated upon. Figure 16 shows how the primary body dimensions were all driven from equations that were defined by the client.

Figure 16 – Parameterised sketch of the main body

Figure 17 and Figure 18 show how the design could be changed easily based on the client’s requests.

Figure 17 – Different configurations

Figure 18 – Global variables with geometries that scale with key dimensions

FLOW SIMULATION & CALCULATION

Figure 19 – Flowvis of low-pressure column through centre

Cloud CFD was used to calculate the flow characteristics through the geometry. The delta mass flows of air through inlet and vent were calculated from equations derived from the changes in pressure across the unit.

CALCULATIONS

By expressing the solubility of air in water as a ratio of volumes:

Equation 1 – Solubility ratio

Known data can be used to calculate the rate of change in solubility as pressure changes. The client has specified the operating temperatures of each unit to be either 45°c or 60°c depending on application. By tabulating data sets from water at or close to these temperatures, a linear equation can be derived from trendlines to calculate the specific solubility at set pressures in each state (Graph 1 and Graph 2).

Graph 1 – Solubility of air in water at 60°c, increasing as pressure rises

Graph 2 – Solubility of air in water at 43.3°c, increasing as pressure rises

CFD simulation provided accurate calculations for water pressure across the inlet and outlet of each geometry (Figure 20 and Table 1). From these figures, the solubility ratio at each point could be calculated, and in turn, the change in volume of dissolved water could be found.

Figure 20 – Simulation setup for standard geometry

From Graph 1:

Equation 2 – 60°c solubility as a function of pressure

And Graph 2:

Equation 3 – Close approximation of 45°c solubility as a function of pressure

These values were tabulated into Table 1.

Table 1 – Solubility ratio at inlet and outlet of each configuration.

Rearranging Equation 1:

Equation 4 – Volume of air as a function of solubility

AIR VOLUME

The volume of air present in the flow at each point in the geometry can be calculated. The delta between inlet and outlet gives the value lost in the system and vented through the top of the geometry (Table 2).

Table 2 – Volume of air present in the flow in each configuration.

Rearranging the ideal gas law can provide the number of mols of gas in the calculated volumes:

Equation 5 – mol of gas at certain pressure and temperature

MASS FLOW RATE

The total mass of air moving throughout the system can then be calculated from the gas’ molar mass:

Equation 6 – Total mass of air calculated from its molecular mass and molar volume

By reintroducing the transient state of calculations per minute, the mass flow rate of air out of each geometry can be calculated accurately.

Table 3 – Calculated mass of air lost per minute through each geometry.

BUBBLE FLOW PATH

The final component of the simulations that was asked by the client was to accurately simulate the flow path of the bubbles of air that were lost through the geometry.

Low columns of static pressure were shown as the closest approximation to a flow path.