【Daily Discussion】Public Utilities – Water Resources and Hydropower – 20210409

Flow disruption for energy dissipation involves using a nose weir to throw the high-speed water flowing downward into the air, causing the water to spread out and mix with a large amount of air. Once it falls back onto the downstream riverbed, it creates intense swirling movements that erode the riverbed and form pits. As these pits deepen, the layer of water on the riverbed becomes thicker; most of the energy is consumed in the friction caused by these swirling movements, and the pits gradually reach a state of stability. Stream guides for energy dissipation are simple and economical, but localized erosion downstream is inevitable; they are generally suitable for high or medium dams with relatively solid bedrock.

Jet dissipator energy dissipation is a method that utilizes the jet apron at the outlet of the water discharge structure to throw the rushing water into the air, where it then falls onto the riverbed farther away from the structure and merges with the downstream flow. Energy consumption is generally divided into three parts: energy dissipation due to friction of the jet along the solid boundary ； The jet frictionates with the air in the air, mixes with air, and dissipates its energy through diffusion ； The jet falls into the downstream tailwater, where turbulent diffusion dissipates the energy. Through the nose weir, picket jet energy dissipation can effectively control the position, range, and flow distribution of the jet as it falls onto the downstream riverbed within the picket jet area. It has strong adaptability to variations in tailwater levels, a simple structure, and is easy to construct and maintain. However, the erosion downstream is severe, with a large amount of sediment; the fluctuations in tailwater and the degree of atomization are also high. Turbine flow dissipators are widely used and suitable for various structures with medium to high head levels and large, medium, or small flow rates.

Flow disruption for energy dissipation involves using a nose weir to throw the high-speed water flowing downward into the air, causing the water to spread out and mix with a large amount of air. After falling back onto the downstream riverbed, this water forms intense vortices that erode the riverbed and create pits. As these pits deepen, the layer of water above them becomes thicker; most of the energy is consumed in the friction caused by these vortices, and eventually the pits stabilize. Stream-guiding energy dissipation structures are relatively simple and economical, but localized erosion downstream is inevitable; they are generally suitable for high or medium dams with relatively solid bedrock. Bottom flow energy dissipation involves installing energy dissipation tanks or weirs downstream of the dam toe to induce water jumps within a defined area, thereby dissipating energy through swirling, friction, aeration, and impact within the water flow. Bottom flow energy dissipation is suitable for medium and low dams or rivers with weak bedrock.

Flow disruption for energy dissipation involves using a nose weir to throw the high-speed water flowing downward into the air, causing the water to spread out and mix with a large amount of air. After falling back onto the downstream riverbed, this water forms intense vortices that erode the riverbed and create pits. As these pits deepen, the layer of water above them becomes thicker; most of the energy is consumed in the friction caused by these vortices, and eventually the pits stabilize. Stream-guiding energy dissipation structures are relatively simple and economical, but localized erosion downstream is inevitable; they are generally suitable for high or medium dams with relatively solid bedrock. Bottom flow energy dissipation involves installing energy dissipation tanks or weirs downstream of the dam toe to induce water jumps within a defined area, thereby dissipating energy through swirling, friction, aeration, and impact within the water flow. Bottom flow energy dissipation is suitable for medium and low dams or rivers with weak bedrock.

Flow disruption for energy dissipation involves using a nose weir to throw the high-speed water flowing downward into the air, causing the water to spread out and mix with a large amount of air. After falling back onto the downstream riverbed, this water forms intense vortices that erode the riverbed and create pits. As these pits deepen, the layer of water above them becomes thicker; most of the energy is consumed in the friction caused by these vortices, and eventually the pits stabilize. Stream-guiding energy dissipation structures are relatively simple and economical, but localized erosion downstream is inevitable; they are generally suitable for high or medium dams with relatively solid bedrock. Bottom flow energy dissipation involves installing energy dissipation tanks or weirs downstream of the dam toe to induce water jumps within a defined area, thereby dissipating energy through swirling, friction, aeration, and impact within the water flow. Bottom flow energy dissipation is suitable for medium and low dams or rivers with weak bedrock.

Jet dissipator energy dissipation is a method that utilizes the jet apron at the outlet of the water discharge structure to throw the rushing water into the air, where it then falls onto the riverbed farther away from the structure and merges with the downstream flow. Energy consumption is generally divided into three parts: energy dissipation due to friction of the jet along the solid boundary ； The jet frictionates with the air in the air, mixes with air, and dissipates its energy through diffusion ； The jet falls into the downstream tailwater, where turbulent diffusion dissipates the energy. Through the nose weir, picket jet energy dissipation can effectively control the position, range, and flow distribution of the jet as it falls onto the downstream riverbed within the picket jet area. It has strong adaptability to variations in tailwater levels, a simple structure, and is easy to construct and maintain. However, the erosion downstream is severe, with a large amount of sediment; the fluctuations in tailwater and the degree of atomization are also high. Turbine flow dissipators are widely used and suitable for various structures with medium to high head levels and large, medium, or small flow rates.

Jet dissipator energy dissipation is a method that utilizes the jet apron at the outlet of the water discharge structure to throw the rushing water into the air, where it then falls onto the riverbed farther away from the structure and merges with the downstream flow. Energy consumption is generally divided into three parts: energy dissipation due to friction of the jet along the solid boundary ； The jet frictionates with the air in the air, mixes with air, and dissipates its energy through diffusion ； The jet falls into the downstream tailwater, where turbulent diffusion dissipates the energy. Through the nose weir, picket jet energy dissipation can effectively control the position, range, and flow distribution of the jet as it falls onto the downstream riverbed within the picket jet area. It has strong adaptability to variations in tailwater levels, a simple structure, and is easy to construct and maintain. However, the erosion downstream is severe, with a large amount of sediment; the fluctuations in tailwater and the degree of atomization are also high. Turbine flow dissipators are widely used and suitable for various structures with medium to high head levels and large, medium, or small flow rates.

Flow disruption for energy dissipation involves using a nose weir to throw the high-speed water flowing downward into the air, causing the water to spread out and mix with a large amount of air. After falling back onto the downstream riverbed, this water forms intense vortices that erode the riverbed and create pits. As these pits deepen, the layer of water above them becomes thicker; most of the energy is consumed in the friction caused by these vortices, and eventually the pits stabilize. Stream-guiding energy dissipation structures are relatively simple and economical, but localized erosion downstream is inevitable; they are generally suitable for high or medium dams with relatively solid bedrock.       Bottom flow energy dissipation involves installing energy dissipation chambers or weirs downstream of the dam foot to induce water jumps within a defined area, thereby dissipating energy through swirling, friction, aeration, and impact within the flow. Bottom flow energy dissipation is suitable for medium and low dams or rivers with weak bedrock.

In flow disruption energy dissipation, a nose weir is used to throw the high-speed water flowing downward into the air, causing the water to spread out and mix with a large amount of air. After falling onto the water cushion in the downstream riverbed, intense swirling occurs, which erodes the riverbed and creates pits. As these pits deepen, the water cushion becomes thicker; most of the energy is consumed in the friction caused by the swirling water, and the pits gradually reach a state of stability. Stream-guiding energy dissipation structures are relatively simple and economical, but localized erosion downstream is inevitable; they are generally suitable for high or medium dams with relatively solid bedrock. Bottom flow energy dissipation involves installing energy dissipation tanks or weirs downstream of the dam toe to induce water jumps within a defined area, thereby dissipating energy through swirling, friction, aeration, and impact within the water flow. Bottom flow energy dissipation is suitable for medium and low dams or rivers with weak bedrock.

Jet dissipator energy dissipation is a method that utilizes the jet apron at the outlet of the water discharge structure to throw the rushing water into the air, where it then falls onto the riverbed farther away from the structure and merges with the downstream flow. Energy consumption is generally divided into three parts: energy dissipation due to friction of the jet along the solid boundary ； The jet frictionates with the air in the air, mixes with air, and dissipates its energy through diffusion ； The jet falls into the downstream tailwater, where turbulent diffusion dissipates the energy. Through the nose weir, picket jet energy dissipation can effectively control the position, range, and flow distribution of the jet as it falls onto the downstream riverbed within the picket jet area. It has strong adaptability to variations in tailwater levels, a simple structure, and is easy to construct and maintain. However, the erosion downstream is severe, with a large amount of sediment; the fluctuations in tailwater and the degree of atomization are also high. Turbine flow dissipators are widely used and suitable for various structures with medium to high head levels and large, medium, or small flow rates.