The design of a racing car needs several aerodynamic design steps in order to achieve high performance. Each component has an aerodynamic interaction with the others and high performance requires a good match between them. The front wing is undoubtedly one of the main components to determine car performance with a strong interaction with the downstream components. The Gurney Flap (GF) is a small appendix perpendicular to the pressure side of the front wing at the trailing edge that can dramatically improve the front wing performance. In the literature, the performance of a GF on a single profile is well documented, while in this paper the GF mounted on the front wing of a racing car has been investigated and the interactions through the 3D flow structures are discussed. The global drag and downforce performance on the main components of the vehicle have been examined by comparing the cases with and without a GF. The GF increases the downforce by about 24% compared to a limited increase in the drag force. A fluid dynamic analysis has been carried out to understand the physical mechanisms of the flow interaction induced to the other components. The GF, in fact, enhances the ground effect, by redistributing the flow that interacts differently with the other components i.e., the wheel zone.

A CFD model to simulate the cooling technique trough slot jet impingement has been developed. Such a technique has been tested on an existing vertical galvanizing industrial line, which initially envisaged a round jet configuration, the subject of a previous work. Two different slot jet configurations have been simulated and compared to the pre-existing one, in order to provide design information for a possible new jet cooler after exploring different solutions. The numerical model has been appropriately calibrated and validated by comparing it with experimental measurements from a literature case. At first, a single slot jet configuration was simulated through a 2D model, then multi slot configurations were calculated using 3D models. Different turbulence models were compared to select the best candidate for the CFD approach. Finally, several configurations with different slots numbers and jet-wall distances were considered. It was possible to understand the physical mechanisms underlying this cooling technique and to be able to select the most promising configuration for the reference industrial cooling process.

The design features of a centrifugal compressor must guarantee high performance and a wide operating range. The ported shroud was developed specifically to extend the operating limit. It is a passive flow control device based on a cavity for flow recirculation to avoid blade passage blocking in near surge conditions. A CFD simulation campaign using a simplified model identified the differences in the performance of the centrifugal compressor with ported shroud, compared to the baseline case. The use of a stability criterion to determine the limit mass flow rate, developed in a previous study by the authors, highlighted and quantified the extension of the surge margin in the case with ported shroud for different rotational speeds. An increase in the surge margin of 11% was detected at design speed, but with a lower trend at higher speeds. An in-depth flow analysis showed the main physical mechanisms in the compressor that occur for different operating conditions: at near surge conditions the cavity recirculates the low momentum flow located in the inducer region; it re-energizes the mainstream decreasing the circumferential velocity component; an improvement of up to 7% of the pressure ratio was obtained. Instead, at best efficiency conditions the flow recirculation worsens the performance by reducing the flow incidence at the rotor leading edge. Finally, using unsteady simulations with a complete 3D model and with the application of the stability criterion it was possible to confirm that the ported shroud can effectively extend the operating range.

The reduction in energy consumption and the increasingly demanding emissions regulations have become strategic challenges for every industrial sector. In this context, the glass industry would be one of the most affected sectors due to its high energy demand and emissions productions, especially in terms of NO_x. For this reason, various emission abatement systems have been developed in this field and one of the most used is the air staging system. It consists in injecting air into the upper part of the regenerative chamber on the exhaust gases side in order to create the conditions for combustion that reduces NO_x emissions. In this work, the combined use of CFD with data analysis techniques offers a tool for the design and management of a hybrid air staging system. Surrogate models of the bypass mass flow rate and uniformity index in the regenerative chamber have been obtained starting from DoE based on different simulations by varying the air mass flow rate of the two injectors located in a bypass duct that connects the two regenerative chambers. This model allows a UQ analysis to verify how the uncertainty of the air injectors can affect the bypass mass flow rate. Finally, an optimization procedure has identified the optimal condition for the best bypass mass flow rates and uniformity of the oxygen concentration in the chamber. High values of the mass flow rate of the pros injector and medium-low values for the cons injectors are identified as operating parameters for best conditions.

The work presents the results of a CFD campaign to investigate the impeller–diffuser interaction in a centrifugal compressor, taking advantage of experimental data from the open literature. Previous studies on the same turbomachine focused on an experimental investigation to understand the flow interaction between the impeller and the vaned diffuser. These experimental data have been used to validate the simulation approach and discuss its results. Several CFD models with increasing complexity have been developed to take into account different aspects. The steady analysis has been performed to highlight the potentials and limitations of such models and to carry out a first study of the flow. In order to analyze the impeller–diffuser interaction, a further model for the unsteady analysis has been set up. Two different operating points have been investigated: one on the surge limit and another in a more stable working zone. A good agreement with the experimental reference data has been obtained with the unsteady analysis and some insights in the complex flow field are deduced.

The search for high aerodynamic performance of a race car is one of the main aspects of the design process. The flow around the basic body shape is complicated by the presence of the rotating wheels. This is especially true in race cars on which the wheels are not shrouded, where the effects on the flow field are considerable. Despite this, few works have focused on the flow around the rotating wheels. In this paper, CFD techniques were used to provide a detailed analysis of the flow structures generated by the interaction between a multielement inverted wing and the wheel of an open-wheel race car. In the first part, the CFD approach was validated for the isolated wheel case by comparing the results with experimental and numerical data from the literature. The wheel was analyzed both in stationary and unsteady flow conditions. Then, the CFD model was adopted to study the interaction of the flow structures between the wheel with the real grooves on the tire and the front wing of a Formula 1 car. Three different configurations were considered in order to differentiate the individual effects. The discussions were supported by the values of the aerodynamic performance coefficients and flow contours.