ADCP's Application to Ocean Current Measurement in Mangalia Port

1. Where is Mangalia port?

Mangalia is a port city in Romania, an important maritime node of a certain scale and throughput. For the scale of the port, it covers a series of berths that can accommodate various vessels, enabling the handling of various cargoes. Besides, the annual throughput shows a stable performance with services for both domestic and international trades.

Regarding the business concern, it is related to more multiple ports in the Black Sea region and also on the Mediterranean Sea and elsewhere through appropriate marine routings. It dealt mainly with goods such as general cargo, containers, and certain bulk cargo.

In the aspect of port management and operation, there are professional teams with the responsibility to guarantee a smooth process in ship berthing, loading and unloading cargo, and the logistics of the whole port. The facility conditions in the port are relatively comprehensive, including modern quay cranes for efficient cargo handling, storage areas with good storage conditions that can store various kinds of goods properly, advanced communication, and navigation facilities to help ships enter and leave safely.

The waterway is well-maintained, and its design allows fulfilling the navigational requirements for ships of various sizes. Besides, it has direct shipping routes with a large number of key ports, which will encourage regional and international trade exchanges and will make it play an important role in the regional maritime transport network.

2. Why should we measure the ocean currents in the Mangalia port?

Ocean currents measured in the Mangalia port contribute much to its operations and management. Firstly, appropriate knowledge of the conditions with regard to ocean currents contributes greatly to the optimization of ships' berthing and unberthing. With appropriate knowledge of velocities and directions, port authorities can schedule times of entry and exit approximately, reducing queueing times, hence better operational efficiency. For example, if the ship knows that there is a strong cross-current around the berth, it can make an appropriate adjustment in approach speed and angle well in advance to ensure smooth and safe docking.

Second, it is important to ensure safety in navigation within the port area; currents affect the maneuverability of ships, and some unexpected strong currents can pose risks such as being swept away from the normal course or experiencing difficulties with stability. Thus, monitoring of ocean currents allows timely warnings to be issued with respect to abnormal current situations for ships to minimize accidents.

In addition to that, the ocean current data proves to be most useful in designing port expansion and infrastructural improvement. It is essential in choosing the optimal places for new berths and the layout of port facilities regarding possible sedimentation or erosion impacts due to currents.

There are traditional ways to measure ocean currents, which in the past had limits regarding accuracy, real-time performance, and convenience. In this direction, the Acoustic Doppler Current Profiler (ADCP) comes up as a more advanced and convenient measurement approach. It can provide detailed and continuous current information in relatively short time with high benefit for operation and management of the Mangalia port.

3. How do ADCPs using the Doppler principle work?

The ADCP current meter operates on the Doppler principle. An ADCP flow meter sends acoustic signals into the water. In this case, when those acoustic waves run into the moving particles in the water, like suspended sediments or small organisms, the frequency of the reflected waves will shift by virtue of the Doppler effect. As already identified above, the velocity of these moving particles, which can be regarded as proportional to the ocean current velocity, can be calculated by comparing the difference between the emitted and the received frequency of the acoustic waves.

There are mainly two kinds of usage of ADCPs in the context of ocean current measurement in the harbor, Mangalia. One usage is that the ADCPs are shipborne. When installed on a ship, while the ship moves through a certain route in port waters, the ADCP current profiler continuously sends acoustic signals downward and around, gathering information of the ocean currents at different depths and positions. This can gain a full understanding of the current situation in the relatively large area of port waters.

The fixed ADCP is another type. It is normally installed in a fixed position in the port, such as on a pier or a submerged structure. It continuously monitors the ocean currents that pass through its position, which may provide long-term and stable current data for analyzing regular patterns and changes of currents in specific areas of the port.

4. What is necessary for high-quality measurement of the currents of Mangalia port?

High-quality measurement of ocean currents in Mangalia port involves a number of aspects related to equipment. First of all, the material reliability of the equipment is at stake. Since the port environment is very aggressive due to such factors as corrosion of seawater and mechanical impacts, the equipment should be manufactured from durable materials.

The preferred characteristics are small in size, light in weight, and low in power consumption. Small in size, it will be easier to install in various positions in the port either on ships or fixed structures. Lighter in weight increases the convenience of transportation and installation, reducing workload and cost. Low power consumption means the equipment can continuously work for a long period without changing the power supply frequently and consuming too much energy.

Besides, lower cost is necessary to be able to measure on a large scale. One of the best options for the casing of ADCP meter is titanium alloy. Titanium alloy has very remarkable advantages: it has high strength that is resistant to the pressure and mechanical forces in an underwater environment; it also has excellent corrosion resistance that is able to resist seawater corrosion for a long time and ensure the equipment's stability and reliability in the long run. Besides, compared with some traditional metal materials, the relatively light weight of FRP makes it more suitable for various installation scenarios in the port.

5. How to Choose the right equipment for current measurement?

When choosing the right equipment for current measurement in the Mangalia port, the purpose of usage should be considered as the main factor. If it is for mobile measurements on ships, the shipborne ADCP will be a good option. It can cover different areas of the port while the ship is navigating around it. In fixed-point, long-term monitoring in specific locations within the port, the bottom-mounted or sit-on-bottom ADCP would be more applicable. It can record the current conditions continuously at that fixed position. If the need is to monitor currents in a wider area and with some mobility while floating on the water surface, then buoy-mounted ADCPs can be considered.

The frequencies of ADCPs should also be chosen according to water depth. For example, for water depth within 70 meters, choice of 600 kHz ADCP is usually appropriate in that it can give fairly accurate current profiles in somewhat shallower waters. The 300 kHz ADCP is used when the water is about 110 meters deep and the 75 kHz would be applied in very deep water up to 1000 meters for reliable measurement results.

There are several well-known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, it is also worth mentioning a Chinese ADCP brand-China Sonar PandaADCP. It's made of all-titanium alloy material, excellent in performance, durable and corrosion-resistant. What is more, it has a very good cost-performance ratio. You can learn more about it on its official website: https://china-sonar.com/.

Finally, ADCP is a very important device to measure the current in the ocean at the Mangalia port; hence, choosing appropriate equipment for a specific need may contribute to effective operations and management of the ports.

Here is a table with some well known ADCP instrument brands and models.