# Physical and Numerical Simulation Study on Structure Optimization of the Inner Wall of Submerged Entry Nozzle for Continuous Casting of Molten Steel

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## Abstract

**:**

## 1. Introduction

## 2. Physical Simulation Research

#### 2.1. Experimental Device and Principle

_{p}= Fr

_{m}, where Fr is the Froude number defined in Equation (2). According to the mold dimensions (1800 mm in length, 1200 mm in width, and 200 mm in thickness), the water flowrate for the model is calculated to be 18.52 m

^{3}/h by using Equation (2).

^{2}/s).

#### 2.2. Structure of Traditional and New-Type Submerged Entry Nozzle for Continuous Casting

#### 2.3. Experimental Results and Discussion

## 3. Numerical Simulation Research

#### 3.1. General Assumptions of the Numerical Model

#### 3.2. Governing Equations

_{eff}is the effective viscosity coefficient.

_{t}the turbulent viscosity; and c

_{1ε}, c

_{2ε}, σ

_{k}, and σ

_{ε}the model constants, which are assigned with values of 1.44, 1.92, 1.0, and 1.3, respectively [15].

#### 3.3. Boundary Conditions and Computation Initialization

#### 3.4. Numerical Simulation Results and Analysis

#### 3.4.1. Influence of Nozzle Type on Flow Field

#### 3.4.2. Effect of Nozzle Type on the Nozzle Outlet Jet

## 4. Conclusions

- (1)
- Compared with the traditional nozzle, the new-type nozzle with internal hemispherical crowns has a shallower molten steel jet impact depth, the impact depth is between 26.5 and 33.61 cm, and the impact angle is between 23 and 29 degrees, and the position of the circuiting zone is closer to the molten steel free surface, which is more conducive to the floating of inclusions. The probability of occurrence of entrapment of top slag is small.
- (2)
- The longitudinal velocity distribution inside the traditional nozzle is uniform. Inside the new-type nozzle, however, transverse velocity components are generated due to the existence of the hemispherical crowns, forming swirl jets at the nozzle outlets with reduced velocity. Therefore, different from the traditional nozzle, the outlet flow from the new-type nozzle is a rotating jet with weaker impact, which is beneficial for using higher casting speed.

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## References

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**Figure 1.**Schematic diagram of the water model experimental set-up. 1. Ladle, 2. tundish, 3. submerged entry nozzle, 4. mold, 5. rotameter, 6. PIV system, and 7. water reservoir.

**Figure 5.**Numerical simulation results of velocity vector fields inside different submerged entry nozzles. The circles shown in Figure 4b stand for the hemispherical crowns.

**Figure 7.**Streamline patterns on a wide-face symmetrical plane of continuous casting mold with different types of submerged entry nozzles.

**Figure 9.**Velocity vector distribution on different cross-sections of traditional and new-type nozzles (c.f., Figure 2 for z-level positions).

**Figure 10.**Velocity vector distributions at steel free surface level in continuous casting mold with different nozzles.

**Figure 11.**Flow state shape (iso-surface of velocity at 1 m/s) of jet at the outlet of different nozzles.

Fluid Media | Density (kg/m^{3}) | Dynamic Viscosity (kg/(m·s)) | Kinematic Viscosity (m^{2}/s) |
---|---|---|---|

Molten steel | 7020 | 6.2 × 10^{−3} | 0.95 × 10^{−6} |

Water | 1000 | 1 × 10^{−3} | 1 × 10^{−6} |

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**MDPI and ACS Style**

Cai, C.; Zhao, M.; Shen, M.; Pan, Y.; Deng, X.; Shi, C.
Physical and Numerical Simulation Study on Structure Optimization of the Inner Wall of Submerged Entry Nozzle for Continuous Casting of Molten Steel. *Processes* **2023**, *11*, 3237.
https://doi.org/10.3390/pr11113237

**AMA Style**

Cai C, Zhao M, Shen M, Pan Y, Deng X, Shi C.
Physical and Numerical Simulation Study on Structure Optimization of the Inner Wall of Submerged Entry Nozzle for Continuous Casting of Molten Steel. *Processes*. 2023; 11(11):3237.
https://doi.org/10.3390/pr11113237

**Chicago/Turabian Style**

Cai, Changyou, Ming Zhao, Minggang Shen, Yuhua Pan, Xin Deng, and Chunyang Shi.
2023. "Physical and Numerical Simulation Study on Structure Optimization of the Inner Wall of Submerged Entry Nozzle for Continuous Casting of Molten Steel" *Processes* 11, no. 11: 3237.
https://doi.org/10.3390/pr11113237