#cfd analysis services

The most appropriate way to get relevant information is to approach a trusted CFD Consulting Services or Structural Analysis Services provider.

 As technology advances, the role of CFD in tunnel safety will continue to grow, ensuring that these critical infrastructures can withstand the challenges posed by fire emergencies.

In modern engineering, Computational Fluid Dynamics (CFD) is vital for optimizing thermal systems. This blog explores a recent CFD thermal analysis performed by Graphler Technology Solutions to evaluate a heat exchanger’s efficiency in transferring heat from a hot fluid (MSW slurry) to a cold fluid (DM water). Here’s what the study uncovered:

The Study Setup

The analysis simulated the heat transfer dynamics between two fluids using steady-state Conjugate Heat Transfer (CHT) analysis. Key parameters included:

Hot fluid (MSW Slurry): Initial temperature of 400°C, flow rate of 0.5 LPM, and inlet pressure of 300 Bar.

Cold fluid (DM Water): Initial temperature of 10°C, flow rate of 38.61 LPM, and inlet pressure of 2 Bar.

The system comprised four heat exchange passes, designed to ensure progressive heat transfer and achieve target temperature levels.

Key Findings

Temperature Distribution

In Pass 1, the hot fluid’s temperature dropped significantly from 400°C to 29.86°C.

Subsequent passes refined the output temperature, with Pass 4 reaching equilibrium at ~10°C.

Heat Transfer Efficiency

The cold fluid flow rate was 77 times higher than the hot fluid’s, driving an aggressive temperature drop.

The heat exchanger required approximately 9–10 meters to align the hot fluid’s temperature with that of the cold fluid.

Material Effectiveness

Stainless steel (Grade 304) and rockwool insulation ensured thermal integrity, with average heat transfer coefficients of:

Cold fluid side: 1027 W/m²-K

Outer insulation: 454 W/m²-K

Energy Implications

The design successfully minimized thermal losses while maintaining the structural and thermal stability of the exchanger.

Material Selection: The use of rockwool insulation and stainless steel proved effective. For future designs, these materials should remain standard, especially for similar operational conditions.

Flow Rate Optimization: High cold fluid flow rates were critical to achieving rapid heat exchange. Depending on energy costs, optimization between flow rates and exchanger length can be explored.

Length Considerations: A total pipe length of 18 meters, with four sequential passes, was adequate for the temperature targets. This insight aids in reducing unnecessary material and space usage in similar designs.

Introduction

Understanding CFD Analysis

CFD is a branch of fluid mechanics that uses numerical analysis and algorithms to solve and analyze problems involving fluid flows. In the context of road tunnels, CFD is used to simulate the behavior of fire and smoke, helping engineers predict their spread and impact under various scenarios.

Key Components of Fire and Smoke CFD Analysis

Fire Dynamics Simulation:

Heat Release Rate (HRR): This is a measure of the energy released by the fire. It is a critical input for CFD simulations as it influences the temperature and smoke production.

Fuel Characteristics: The type of materials involved in the fire affects the combustion process, influencing smoke production and toxicity.

Smoke Behavior and Dispersion:

Smoke Movement: CFD models predict how smoke travels through the tunnel, considering factors such as ventilation systems, tunnel geometry, and traffic conditions.

Visibility and Toxicity: The simulation assesses how smoke affects visibility and air quality, crucial for evacuation and rescue operations.

Ventilation Systems:

Natural Ventilation: Utilizes the tunnel’s design and natural airflow to manage smoke.

Mechanical Ventilation: Involves fans and other mechanical systems to control smoke spread and ensure clear escape routes.

Emergency Response:

Evacuation Modeling: CFD helps in planning and optimizing evacuation routes and procedures, ensuring that people can exit the tunnel safely and quickly.

Firefighting Strategies: Simulations can evaluate the effectiveness of different firefighting tactics and equipment placement.

Applications and Benefits of CFD Analysis

Design Optimization: Engineers use CFD to optimize tunnel design, ensuring that ventilation systems and safety measures are effective in controlling fire and smoke.

Risk Assessment: By simulating various fire scenarios, CFD helps in identifying potential risks and weak points in the tunnel design.

Regulatory Compliance: CFD analysis supports compliance with safety standards and regulations, providing evidence of the tunnel’s ability to handle fire emergencies.

Training and Preparedness: Emergency response teams can use CFD simulations for training, improving their readiness and effectiveness in real-world scenarios.

Challenges and Future Directions

While CFD analysis offers significant benefits, it also presents challenges. Accurate simulations require detailed input data and considerable computational resources. Additionally, real-world conditions can be complex and variable, making it difficult to account for all possible scenarios.

Conclusion

Fire and smoke CFD analysis is an indispensable tool in the design and management of road tunnels. By providing detailed insights into fire dynamics and smoke behavior, it helps engineers create safer environments and develop effective emergency strategies. As technology advances, the role of CFD in tunnel safety will continue to grow, ensuring that these critical infrastructures can withstand the challenges posed by fire emergencies.

Inorder to reduce higher cooling demands for buildings or industries, passive cooling by night-time flushing can be seen as a promising option. Particularly in tropical and sub-tropical climates where the difference in peak day-time and night-time temperature is about 10˚C – 13˚C.

Those buildings with high thermal mass benefit the most in this type of strategy.

The natural ventilation system can bring in cool air during night, thereby reducing the temperature of the internal fabric of the building.

Night time cooling generally provides 1.5˚C – 2˚C lower than the outside during day time peak temperature. This also reduces the need for mechanical cooling for few hours during the day.

It also helps to flush stale air, odors, irritants etc. from the building/industry which was produced during the day time operation.

Scope of presented work

In this case study, the effect of night-time ventilation is validated for natural ventilation and hybrid ventilation (with existing mechanical ventilators running at full capacity) during a peak summer day.

Comparing the results for both strategies to visualize the effect of day-time indoor temperature.

Approach and methodology  

The whole Industry is modelled with all machines, support structures like columns, beams etc.

CFD simulations is performed for 24 hours in a peak summer day. During the day time operation, the internal loads coupled with solar heat gain is simulated.

Thickness of cladding and roofing sheets were considered along with thermal insulation on the roof.

Fan performance curve is used for modelling ventilators in case of hybrid ventilation.

All shutters, doors, and windows we considered 90% open on all sides during night time.

In this analysis it is assumed that the night-time ventilation starts at 19hrs and ends at 7hrs.  

Solution from CFD analysis:

From numerical simulations it is evident that the night flushing has significant effect in controlling the thermal behavior of the internal fabric of the Industrial building.

Transient analysis performed during evening hours shows fall in temperature of machines and the overall internal temperature of the building.

Cooling the thermal mass during night provides radiative cooling for day time operation, thereby increasing the thermal comfort at the working level.

This thermal lag during day time is detrimental in con­trolling the internal temperature of the building during peak hours.

It has reduced the overall heat load inside the building during operations for the next day.

Introduction:

The mixed-flow submersible pumps are used for domestic purpose and also at the commercial level in a large extent, so increasing the efficiency of the pump is an essential part. Design of multi stage pump is really complex due to the fact that the flow inside this pump is inherently complex in nature. With the rapid development of the computer technology, the Computational fluid dynamics (CFD) and the numerical simulation has become an important tool to study flow field inside the pump and predict its performance.

With the aid of the CFD technology, the complex internal flows in water pump impellers can be well predicted and speed up the design procedure. Thus, CFD is an important tool for pump designers since it will reduce the time consuming and expensive experimental procedures.

Scope of Work:

Predict the performance improvement of Bowl-Impeller Axial Gap in a multi stage mixed flow submersible pump.

Six different Bowl-Impeller axial gap variations were considered (vary from 2mm, 5mm and 10 mm in Increasing and Decreasing order ).

Taguchi Method is utilized to reduce the number of trials and to optimize the best performance.

With a goal of increasing hydraulic efficiency of the pump CFD is utilized in a following systematic way.

Validation Study: CFD procedure has lot of variables such as grid count, turbulence model, and discretization scheme, so it is important for a CFD engineer to play between those variables without

affecting the solution accuracy. A commercial Computational Fluid Dynamics (CFD) code with a k-£ Realizable turbulence model was used to study the effects of Bowl-Impeller Interaction. Moving Reference Frame (MRF) technique is used to numerically model the rotation of the impeller section to predict the flow behaviour of the pump.

The numerical results are compared with the experimental data of the base model to arrive at the best computational procedure (BCP). Consult a reputable CFD consulting service or an Engineering Animation Services company to gain precise knowledge.

Performance Enhancement Study:

The hydraulic performance of the pump highly depends upon the complex configuration of the Bowl-Impeller interaction, number of blades on bowl-impeller, inlet-outlet angles, radial and axial clearance between Bowl-impeller and other various dimensions such as diameter, width etc., In this case axial clearance, number of blades and outlet angle on impeller are taken as the major variables for optimization.

Utilization of DOE Methodology

Taguchi method is a scientifically disciplined mechanism for evaluating and implementing improvements in products, processes, materials, equipment, and facilities. These improvements are aimed at improving the desired characteristics and simultaneously reducing the number of defects by studying the key variables controlling the process and optimizing the procedures or design to yield the best results.